¿ªÔÆÌåÓý

Date

Re: New to group and Query

bambazonke01
 

---
Hi Allison,
I'd never thought of WWV being a problem in this respect in North
America. You are right.It would be annoying to hear that Tick -tick
all the time.
I will have to consider some other IF frequency. First I'll have to
see what crystals are available locally and redesign the ladder filter.
Did you know that TEn Tec used to use CB crystals for their early
filters?
The 27+ Mhz crystals are 3 rd ovetone types so operating on the
fundamental frequency gave 9 mHz. That is why the filters were
slightly above 9 mhz. I like the idea of 9 Mhz as with the 5 to 5.5
Mhz VFO we could operate 2 bands (80 and 20)
I was searching through packing crates today for my PC manufacturing
stuff without finding any. Some where I have a great setup of ultra
violet light and timer etc. I may have to go out and buy new ones.
73
Jim VE3DDY


Re: New to group and Query

ajparent1
 

Hello,

Comments are inserted inline.

--- In BITX20@..., "bambazonke01" <jimandruth@s...> wrote:
Most of this V3 board is IF and BFO and as such is well shielded by
the prolific ground plane on it's single side.I like this type of
layout as it avoids a lot of ground loop problems.
I prefer a two sided board where the component side has no
traces only clearance holes for non grounded components and
holes that are not clearanced so grounded components can be
soldered to it the ground plane. The bottom then only has +power
and signals simplifying layout. The inherent shielding is excellent
with this layout and only side need be "drawn".

I have found shielding is always helpful. For those of us here(USA)
or near WWV at 10mhz can be problematic.

To get up to 6 meters I would presume you are going to heterodyne
the signal and have the final on a separate CCA. The hetrodyne
oscillator and final can be seperately well shielded from the IF and
VFO otherwise you are going to have more trouble than a barrel full
of monkeys with all the signals mixing .
This will be the 6th design for 6m I've done. Each being
significantly different in some way from previous. This will
be the first using a bidirectional IF and single conversion.
Design #5 is a BIT-X at 20m driving a TenTec 1208(or any other!)
transverter for 6M naking it dual conversion. That design (#5)
will be modded for 10M use and a later 432mhz transverter.

It's not nearly the problem if the frequencies are chosen right
and the mixer is not overloaded. I have done many a hetrodyne LO
before with excellent results. A VFO of 5mhz range and a crystal
osc at 36mhz works with a 9mhz IF for coverage of 50.0 to 50.5mhz.
The VFO and Crystal osc can be in the same module with a DBM and
the DBM output goes to a seperate module with a three tuned circuit
bandpass filter at 41mhz and output amplifer. Measured spurs were
more than 70db down at the output of the filter amp module. Much of
the work I've done with hetrodyne LO systems is well documented by
others in EMDRF.

However, this version will use a sampling PLL system of my design.
I have four of these working in various radios with the only
difference being the output frequency. The PLL is already complete
and the whole module uses 70ma and provides a 10DBm output for the
mixer in a package of 40mmx40mmx22mm. This verion will have a LO at
40.4 through 40.700 (tunes 50.0 to 50.300). I should gen up a block
diagram of this system as it's somewhat simpler and does not require
a microprocessor for tuning.

Variations on the BITx design I will be using is a commercial DBM
for the mixer (I have a bunch of SBL1/anzac108). I will put a MPF102
fet preamplifier before the bandpass filter as it's fairly lossy and
at 6m you need a good signal to noise for weak signals. In the RX
path after Q1 a PIN(poor mans PIN, 1n4007) diode attenuator for RX
AGC. AGC voltage will be audio derived. The amplifiers on the VHF
side of the DBM will be 2n5109 or 2n5176 types (Ft >1ghz). The IF
because of WWV will be 9.6mhz. Power amplifier chain will use a
2N4124, 2n5109 and 2SC1971. There may be other changes as I experiment.

Power amplifier chain will be split fairly similar to the base BIT-x
where the 2N4124 buffer (Q14) in on the main board and the driver and
final on a seperate board. I do this for two reasons. I have a good
quanitity of 2.4" wide G10 copper clad board strips of 50-60cm long
and I may later wish a different power amp design.

Hope this give some detail on how I will go about it.

FYI: My passtime is QRP 6M and 2M weak signal work.

Regards,
Allison
KB1GMX

Best of luck
Jim VE3DDY

--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:

Hi,

It's size and the lack of two sides (top ground plane) make it
less than useful for my 6m project. I'm saving it for something
else. I mentioned it so others may know that FAR has it.

Myself I'm dead bugging it [aka ugly or manhattan] style as its
fast and offers good grounding and shielding. I have PCB making
materials but for one off stuff it's as much time to setup and
do that is just building it dead bug style. Also much smaller.
FYI: I'm targeting a 175x45x130mm package. Power output will be
in the 3-5w range with 2SC1971 transistor. So I understand you
goal for containing in a manpack.

Allison
KB1GMX

--- In BITX20@..., "bambazonke01" <jimandruth@s...>
wrote:
The Far circuits boards are away too big for my application so
I'm
strongly considering a run of the CCA design by VU3WJM (Rahul).
This board design is 6.5 X 4.25 inches and will fit nicely
inside
the Chinese 884 VHF packset which you can buy off E-bay (Call
up "Military Radio")
I've recently relocated homes and will have to restock on G10
pcb
and resist etc.
Jim VE3DDY


--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:
Hello,

This may not be of help to everyone but for North Americans
it would be handy to know.

FAR circuits www.farcircuits.net

They have the the BIT-X board as drawn by the creator.
The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
for the non metric]. At 19.00$US it's expensive but may
save construction time.

Allison,
KB1GMX

--- In BITX20@..., Rahul Srivastava <vu3wjm@y...>
wrote:
Hi! Friends

Unfortunately we have still not managed to get the BITX PCB
commercialy manufactured even though it is quite cheap getting
it
done
here.
Secondly postage from India is also rather expensive ie
much
more
than the board.
Board is correct in all respect except for one hole missing
for a
resistor but that anchors to nearby component lead. Ver3 is
quite
stable too. I would be happy if some DX friends can help out
in
this
matter to all those who need PCB. I will be happy to provide
any
needed file.

The modified filter response posted by one of our french
friend
does
indeed results in improved audio. I use 82,120&150pf caps as
standard
value.



I have yet to try swaping the PD/MOD connection mod.

Lately I came across another minimalist design. Less the uC
section
and brass screw PTO it becomes quite attractive



73

Raahul VU3WJM






bambazonke01 <jimandruth@s...> wrote:
Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits
the
884
packset like a glove. I have to find someone who has that
board
available or else gear up to make my own. I've made some
PCB's
in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay
for
about
$120 Canadian or $100 US. These sets are good for 6 meter
FM
but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always
enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In
the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans <arvevans@e...>
wrote:
Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB,
including
the
PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
power switching. It is a bit tight, but it can be done.
Since
the RF stages
require shielding from the lower power sections, the use
of
vertical sections
of blank PCB might allow parts of the circuit to be built
on
these
shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well
if
you
prefer that
method of construction. Some of the PCB layouts are
documented in
the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several
smaller
modules (about
1 inch by 2 inches) that were then assembled to make up a
very
compact
layout.

By all means, read over the older email messages, then go
to
the
FILES and the
PHOTO sections and review what is there. You will find
several
additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run
into
problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._
On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into
which
I'd
like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA
modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo!
Terms of
Service.




SPONSORED LINKS
Craft hobby Hobby and craft supply Ham radio Hobby supply
Ham
radio
sales

---------------------------------
YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms
of
Service.


---------------------------------




---------------------------------
To help you stay safe and secure online, we've developed the
all
new
Yahoo! Security Centre.


Re: New to group and Query

bambazonke01
 

Most of this V3 board is IF and BFO and as such is well shielded by
the prolific ground plane on it's single side.I like this type of
layout as it avoids a lot of ground loop problems.
To get up to 6 meters I would presume you are going to heterodyne
the signal and have the final on a separate CCA. The hetrodyne
oscillator and final can be seperately well shielded from the IF and
VFO otherwise you are going to have more trouble than a barrel full
of monkeys with all the signals mixing .
Best of luck
Jim VE3DDY

--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:

Hi,

It's size and the lack of two sides (top ground plane) make it
less than useful for my 6m project. I'm saving it for something
else. I mentioned it so others may know that FAR has it.

Myself I'm dead bugging it [aka ugly or manhattan] style as its
fast and offers good grounding and shielding. I have PCB making
materials but for one off stuff it's as much time to setup and
do that is just building it dead bug style. Also much smaller.
FYI: I'm targeting a 175x45x130mm package. Power output will be
in the 3-5w range with 2SC1971 transistor. So I understand you
goal for containing in a manpack.

Allison
KB1GMX

--- In BITX20@..., "bambazonke01" <jimandruth@s...>
wrote:
The Far circuits boards are away too big for my application so
I'm
strongly considering a run of the CCA design by VU3WJM (Rahul).
This board design is 6.5 X 4.25 inches and will fit nicely
inside
the Chinese 884 VHF packset which you can buy off E-bay (Call
up "Military Radio")
I've recently relocated homes and will have to restock on G10
pcb
and resist etc.
Jim VE3DDY


--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:
Hello,

This may not be of help to everyone but for North Americans
it would be handy to know.

FAR circuits www.farcircuits.net

They have the the BIT-X board as drawn by the creator.
The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
for the non metric]. At 19.00$US it's expensive but may
save construction time.

Allison,
KB1GMX

--- In BITX20@..., Rahul Srivastava <vu3wjm@y...>
wrote:
Hi! Friends

Unfortunately we have still not managed to get the BITX PCB
commercialy manufactured even though it is quite cheap getting
it
done
here.
Secondly postage from India is also rather expensive ie
much
more
than the board.
Board is correct in all respect except for one hole missing
for a
resistor but that anchors to nearby component lead. Ver3 is
quite
stable too. I would be happy if some DX friends can help out
in
this
matter to all those who need PCB. I will be happy to provide
any
needed file.

The modified filter response posted by one of our french
friend
does
indeed results in improved audio. I use 82,120&150pf caps as
standard
value.



I have yet to try swaping the PD/MOD connection mod.

Lately I came across another minimalist design. Less the uC
section
and brass screw PTO it becomes quite attractive



73

Raahul VU3WJM






bambazonke01 <jimandruth@s...> wrote:
Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits
the
884
packset like a glove. I have to find someone who has that
board
available or else gear up to make my own. I've made some
PCB's
in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay
for
about
$120 Canadian or $100 US. These sets are good for 6 meter
FM
but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always
enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In
the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans <arvevans@e...>
wrote:
Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB,
including
the
PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
power switching. It is a bit tight, but it can be done.
Since
the RF stages
require shielding from the lower power sections, the use
of
vertical sections
of blank PCB might allow parts of the circuit to be built
on
these
shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well
if
you
prefer that
method of construction. Some of the PCB layouts are
documented in
the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several
smaller
modules (about
1 inch by 2 inches) that were then assembled to make up a
very
compact
layout.

By all means, read over the older email messages, then go
to
the
FILES and the
PHOTO sections and review what is there. You will find
several
additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run
into
problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._
On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into
which
I'd
like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA
modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo!
Terms of
Service.




SPONSORED LINKS
Craft hobby Hobby and craft supply Ham radio Hobby supply
Ham
radio
sales

---------------------------------
YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms
of
Service.


---------------------------------




---------------------------------
To help you stay safe and secure online, we've developed the
all
new
Yahoo! Security Centre.


Re: New to group and Query

ajparent1
 

Hi,

It's size and the lack of two sides (top ground plane) make it
less than useful for my 6m project. I'm saving it for something
else. I mentioned it so others may know that FAR has it.

Myself I'm dead bugging it [aka ugly or manhattan] style as its
fast and offers good grounding and shielding. I have PCB making
materials but for one off stuff it's as much time to setup and
do that is just building it dead bug style. Also much smaller.
FYI: I'm targeting a 175x45x130mm package. Power output will be
in the 3-5w range with 2SC1971 transistor. So I understand you
goal for containing in a manpack.

Allison
KB1GMX

--- In BITX20@..., "bambazonke01" <jimandruth@s...> wrote:
The Far circuits boards are away too big for my application so I'm
strongly considering a run of the CCA design by VU3WJM (Rahul).
This board design is 6.5 X 4.25 inches and will fit nicely inside
the Chinese 884 VHF packset which you can buy off E-bay (Call
up "Military Radio")
I've recently relocated homes and will have to restock on G10 pcb
and resist etc.
Jim VE3DDY


--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:
Hello,

This may not be of help to everyone but for North Americans
it would be handy to know.

FAR circuits www.farcircuits.net

They have the the BIT-X board as drawn by the creator.
The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
for the non metric]. At 19.00$US it's expensive but may
save construction time.

Allison,
KB1GMX

--- In BITX20@..., Rahul Srivastava <vu3wjm@y...>
wrote:
Hi! Friends

Unfortunately we have still not managed to get the BITX PCB
commercialy manufactured even though it is quite cheap getting it
done
here.
Secondly postage from India is also rather expensive ie much
more
than the board.
Board is correct in all respect except for one hole missing for a
resistor but that anchors to nearby component lead. Ver3 is quite
stable too. I would be happy if some DX friends can help out in
this
matter to all those who need PCB. I will be happy to provide any
needed file.

The modified filter response posted by one of our french friend
does
indeed results in improved audio. I use 82,120&150pf caps as
standard
value.



I have yet to try swaping the PD/MOD connection mod.

Lately I came across another minimalist design. Less the uC
section
and brass screw PTO it becomes quite attractive



73

Raahul VU3WJM






bambazonke01 <jimandruth@s...> wrote:
Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits the
884
packset like a glove. I have to find someone who has that board
available or else gear up to make my own. I've made some PCB's
in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay for
about
$120 Canadian or $100 US. These sets are good for 6 meter FM
but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans <arvevans@e...> wrote:
Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB,
including
the
PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
power switching. It is a bit tight, but it can be done.
Since
the RF stages
require shielding from the lower power sections, the use of
vertical sections
of blank PCB might allow parts of the circuit to be built on
these
shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well if
you
prefer that
method of construction. Some of the PCB layouts are
documented in
the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several
smaller
modules (about
1 inch by 2 inches) that were then assembled to make up a very
compact
layout.

By all means, read over the older email messages, then go to
the
FILES and the
PHOTO sections and review what is there. You will find
several
additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run into
problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._
On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into which
I'd
like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA
modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.




SPONSORED LINKS
Craft hobby Hobby and craft supply Ham radio Hobby supply Ham
radio
sales

---------------------------------
YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.


---------------------------------




---------------------------------
To help you stay safe and secure online, we've developed the all
new
Yahoo! Security Centre.


I found these in my junk box

Jim Strohm
 

Hi

The last time this item surfaced, I was selling it for a dollar a foot. I think I can do that again.

It's a reel of 20 pF NP0 disc capacitors on paper tape, with 1 inch leads, 24 per foot. That's 2.5 cm, 75 parts per meter.

I think I'm down to about 1,000 pieces, which is more than I can use in my lifetime. I won't sell it all in one piece, but I'd gladly share most of it. If there's interest, drop me an email. 3 feet (1 m) comes to about 1 ounce net wt. and I'll mail internationally. Foreign currency happily accepted.

Jim N6OTQ
n6otq@...
or -- n6otq at yahoo dot com if the email munger is still running


Re: New to group and Query

bambazonke01
 

Thanks Rahul
Jim VE3DDY
--- In BITX20@..., Rahul Srivastava <vu3wjm@y...> wrote:
Hi!

For those going in for ver3 board , I once again repeat the mods.

1) Q1 I have used 2SC2570A a high ft cable TV transistor for
higher gain and lower NF. So the pin out is B-E-C which is different
from other transistors. C-B-E L-R for other devices. For 2SC2570
you cab also substitute BFR90.91,96 or MPS571 etc type. Lately one
more interestind transistor I have come across 2SC1393/94 this is
used is portable BW TV tuners and is easily available.

2) Mixer is now doubly balanced so one more trifilar binocular
core to wind.

3)Q13 has one pad missing on 100 E collector supply resistor but
that can be tagged to the adjacent 220E resistor lead on top of
board.

4)Q3 has been replaced by 2 transistor shunt feedback amplifier.
However if you wish ,there are sufficient spare holes to retain the
original circuitry.
As a result of added ckt you can reduce 2K2 feedbak C-B resistor
on Q11 for slightly improved match.

5) Frontend bandpass uses 10mm adjustable coils. I have used 2.7uh
10.7mhz readymade FM radio IF coils with caps changed. You can roll
your own, value can be in range of 2-2.7uH. The coupling has been
also changed to 2 turn link type.

6) BFO has now a abt 6uH inductor in series for proper and smooth
setting of freq.

7) VFO has provision for both tuning by variable capacitor or
varicap as well as to configure as series tuned colpitts.

8)LM386 has a .001uF bypass on pin 3 for better stability and a
220uF cap on output for improved LF response.

With bit care the rigs comes on in one go.

73

Rahul VU3WJM

PS: Do the filter cap changes it results in much improved TX
audio.


bambazonke01 <jimandruth@s...> wrote:
The Far circuits boards are away too big for my application so I'm
strongly considering a run of the CCA design by VU3WJM (Rahul).
This board design is 6.5 X 4.25 inches and will fit nicely inside
the Chinese 884 VHF packset which you can buy off E-bay (Call
up "Military Radio")
I've recently relocated homes and will have to restock on G10 pcb
and resist etc.
Jim VE3DDY


--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:
Hello,

This may not be of help to everyone but for North Americans
it would be handy to know.

FAR circuits www.farcircuits.net

They have the the BIT-X board as drawn by the creator.
The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
for the non metric]. At 19.00$US it's expensive but may
save construction time.

Allison,
KB1GMX

---------------------------------
Yahoo! Messenger NEW - crystal clear PC to PC calling worldwide
with voicemail


Re: New to group and Query

Rahul Srivastava
 

Hi!
?
For those going in for ver3 board , I once again repeat the mods.
?
1) Q1 I have used 2SC2570A a high ft cable TV transistor for higher gain and lower NF. So the pin out is B-E-C which is different from other transistors. C-B-E? L-R for other devices. For 2SC2570?you cab also substitute BFR90.91,96?or MPS571 etc type. Lately one more interestind transistor I have come across 2SC1393/94 this is used is portable BW TV tuners and is easily available.??
?
2) Mixer is now doubly balanced so one more trifilar binocular? core to wind.
?
3)Q13 has one pad missing on 100?E collector supply resistor but that can be tagged to the adjacent 220E resistor lead on top of board.
?
4)Q3 has been replaced by 2 transistor shunt feedback amplifier. However if you wish ,there are sufficient spare holes to retain the original circuitry.
As a result of added ckt you can reduce 2K2 feedbak C-B resistor on Q11 for slightly improved match.
?
5) Frontend bandpass uses 10mm adjustable coils. I have used 2.7uh 10.7mhz readymade FM radio IF coils with caps changed. You? can roll your own,? value can be in range of 2-2.7uH. The coupling has been also changed to 2 turn link type.
?
6) BFO has now a abt 6uH inductor in series for proper and smooth setting of freq.
?
7) VFO has provision for both tuning by variable capacitor or varicap as well as to configure as series tuned colpitts.
?
8)LM386 has a .001uF bypass on pin 3 for better stability and a 220uF cap on output for improved LF response.
?
With bit care the rigs comes on in one go.
?
73
?
Rahul VU3WJM
?
PS: Do the filter cap changes it results in much improved TX audio.?
?
?
bambazonke01 wrote:
The Far circuits boards are away too big for my application so I'm
strongly considering a run of the CCA design by VU3WJM (Rahul).
This board design is 6.5 X 4.25 inches and will fit nicely inside
the Chinese 884 VHF packset which you can buy off E-bay (Call
up "Military Radio")
I've recently relocated homes and will have to restock on G10 pcb
and resist etc.
Jim VE3DDY


--- In BITX20@..., "ajparent1" wrote:
> Hello,
>
> This may not be of help to everyone but for North Americans
> it would be handy to know.
>
> FAR circuits? www.farcircuits.net
>
> They have the the BIT-X board as drawn by the creator.?
> The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
> for the non metric].? At 19.00$US it's expensive but may
> save construction time.
>
> Allison,
> KB1GMX
>
>


NEW - crystal clear PC to PC


Re: New to group and Query

bambazonke01
 

The Far circuits boards are away too big for my application so I'm
strongly considering a run of the CCA design by VU3WJM (Rahul).
This board design is 6.5 X 4.25 inches and will fit nicely inside
the Chinese 884 VHF packset which you can buy off E-bay (Call
up "Military Radio")
I've recently relocated homes and will have to restock on G10 pcb
and resist etc.
Jim VE3DDY


--- In BITX20@..., "ajparent1" <kb1gmx@a...> wrote:
Hello,

This may not be of help to everyone but for North Americans
it would be handy to know.

FAR circuits www.farcircuits.net

They have the the BIT-X board as drawn by the creator.
The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
for the non metric]. At 19.00$US it's expensive but may
save construction time.

Allison,
KB1GMX

--- In BITX20@..., Rahul Srivastava <vu3wjm@y...>
wrote:
Hi! Friends

Unfortunately we have still not managed to get the BITX PCB
commercialy manufactured even though it is quite cheap getting it
done
here.
Secondly postage from India is also rather expensive ie much
more
than the board.
Board is correct in all respect except for one hole missing for a
resistor but that anchors to nearby component lead. Ver3 is quite
stable too. I would be happy if some DX friends can help out in
this
matter to all those who need PCB. I will be happy to provide any
needed file.

The modified filter response posted by one of our french friend
does
indeed results in improved audio. I use 82,120&150pf caps as
standard
value.



I have yet to try swaping the PD/MOD connection mod.

Lately I came across another minimalist design. Less the uC
section
and brass screw PTO it becomes quite attractive



73

Raahul VU3WJM






bambazonke01 <jimandruth@s...> wrote:
Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits the
884
packset like a glove. I have to find someone who has that board
available or else gear up to make my own. I've made some PCB's
in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay for
about
$120 Canadian or $100 US. These sets are good for 6 meter FM
but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans <arvevans@e...> wrote:
Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB,
including
the
PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
power switching. It is a bit tight, but it can be done.
Since
the RF stages
require shielding from the lower power sections, the use of
vertical sections
of blank PCB might allow parts of the circuit to be built on
these
shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well if
you
prefer that
method of construction. Some of the PCB layouts are
documented in
the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several
smaller
modules (about
1 inch by 2 inches) that were then assembled to make up a very
compact
layout.

By all means, read over the older email messages, then go to
the
FILES and the
PHOTO sections and review what is there. You will find
several
additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run into
problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._
On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into which
I'd
like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA
modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.




SPONSORED LINKS
Craft hobby Hobby and craft supply Ham radio Hobby supply Ham
radio
sales

---------------------------------
YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.


---------------------------------




---------------------------------
To help you stay safe and secure online, we've developed the all
new
Yahoo! Security Centre.


Re: New to group and Query

ajparent1
 

Hello,

This may not be of help to everyone but for North Americans
it would be handy to know.

FAR circuits www.farcircuits.net

They have the the BIT-X board as drawn by the creator.
The one I have measures 221mm by 82mm [8 11/16" by 3 1/4"
for the non metric]. At 19.00$US it's expensive but may
save construction time.

Allison,
KB1GMX

--- In BITX20@..., Rahul Srivastava <vu3wjm@y...> wrote:
Hi! Friends

Unfortunately we have still not managed to get the BITX PCB
commercialy manufactured even though it is quite cheap getting it done
here.
Secondly postage from India is also rather expensive ie much more
than the board.
Board is correct in all respect except for one hole missing for a
resistor but that anchors to nearby component lead. Ver3 is quite
stable too. I would be happy if some DX friends can help out in this
matter to all those who need PCB. I will be happy to provide any
needed file.

The modified filter response posted by one of our french friend does
indeed results in improved audio. I use 82,120&150pf caps as standard
value.



I have yet to try swaping the PD/MOD connection mod.

Lately I came across another minimalist design. Less the uC section
and brass screw PTO it becomes quite attractive



73

Raahul VU3WJM






bambazonke01 <jimandruth@s...> wrote:
Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits the 884
packset like a glove. I have to find someone who has that board
available or else gear up to make my own. I've made some PCB's in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay for about
$120 Canadian or $100 US. These sets are good for 6 meter FM but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans <arvevans@e...> wrote:
Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB, including
the
PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
power switching. It is a bit tight, but it can be done. Since
the RF stages
require shielding from the lower power sections, the use of
vertical sections
of blank PCB might allow parts of the circuit to be built on these
shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well if you
prefer that
method of construction. Some of the PCB layouts are documented in
the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several smaller
modules (about
1 inch by 2 inches) that were then assembled to make up a very
compact
layout.

By all means, read over the older email messages, then go to the
FILES and the
PHOTO sections and review what is there. You will find several
additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run into
problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._
On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into which I'd
like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.




SPONSORED LINKS
Craft hobby Hobby and craft supply Ham radio Hobby supply Ham radio
sales

---------------------------------
YAHOO! GROUPS LINKS


Visit your group "BITX20" on the web.

To unsubscribe from this group, send an email to:
BITX20-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.


---------------------------------




---------------------------------
To help you stay safe and secure online, we've developed the all new
Yahoo! Security Centre.


Re: New to group and Query

Rahul Srivastava
 

Hi! Friends
?
Unfortunately we have still not managed to get the BITX PCB?commercialy manufactured even though it is quite cheap getting it done here.
?Secondly postage from India is also rather expensive ie much more than the board.
Board is correct in all respect except for one?hole missing for a resistor but that anchors to nearby component lead. Ver3 is quite stable too. I would be happy if some DX friends can help out in this matter to all those who need? PCB. I will be happy to provide any needed file.
?
The modified filter response posted by one of our french friend?does indeed results in improved audio. I use 82,120&150pf caps as standard value.
?
?
?
I?have yet to try swaping the PD/MOD connection mod.
?
Lately I came across another minimalist design. Less the uC section and brass screw PTO it becomes quite attractive
?
?
73
?
Raahul VU3WJM
?
?
?
?


bambazonke01 wrote:
Hi Arv, and Group,
I've been looking at the CCA? Version 3 by VU3WJM as it fits the 884
packset like a glove. I have to find someone who has that board
available or else gear up to make my own. I've made some PCB's in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay for about
$120 Canadian or $100 US. These sets are good for 6 meter FM? but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans wrote:
> Jim VE3DDY
>
> One of my BITX units is built on a 7 inch by 4 inch PCB, including
the
> PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
> power switching.? It is a bit tight, but it can be done.? Since
the RF stages
> require shielding from the lower power sections, the use of
vertical sections
> of blank PCB might allow parts of the circuit to be built on these
shielding
> partitions, thus allowing a more compact design.
>
> PCBs have been designed and may still be available as well if you
prefer that
> method of construction.? Some of the PCB layouts are documented in
the FILES
> and PHOTO sections of the forum.
>
> Some BITX builders have constructed the unit in several smaller
modules (about
> 1 inch by 2 inches) that were then assembled to make up a very
compact
> layout.
>
> By all means, read over the older email messages, then go to the
FILES and the
> PHOTO sections and review what is there.? You will find several
additional
> ideas for modification and upgrades.
>
> Welcome aboard and good luck with your BITX.? If you run into
problems, there
> are many now on the BITX forum that may be able to help.
>
> Arv K7HKL
> _._
>? On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
> >? Hi BIT-X'ers,
> >? My name is Jim and I'm new to the group.
> >? I'm a Canadian Radio Amateur and an avid experimenter.
> >? I have an old Chinese type 884 VHF radio packset into which I'd
like
> >? to install a Bit-X perhaps for 40 Meters.
> >? Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
> >? approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
> >? I also have similar size available for the VFO and PA modules.
> >? I've lots of reading to catch up on.
> >? Jim VE3DDY
> >
> >
> >
> >
> >? YAHOO! GROUPS LINKS
> >
> >
> > ?Visit your group "BITX20" on the web.
> > ?
> > ?To unsubscribe from this group, send an email to:
> > ?BITX20-unsubscribe@...
> > ?
> > ?Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.



To help you stay safe and secure online, we've developed the all new .


Re: New to group and Query

bambazonke01
 

Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits the 884
packset like a glove. I have to find someone who has that board
available or else gear up to make my own. I've made some PCB's in
the past. I think Far Circuits may make me one as well.
You may have seen the 884 VHF packset being sold on e-bay for about
$120 Canadian or $100 US. These sets are good for 6 meter FM but
they are ideal to use for a rebuild in an HF packset.
I have al kinds of HF gear and "Green Radios" but always enjoy a
project like this BitX.
As time goes on PCB problems will sort themselves out. In the
meantime, I'll start collecting components.
Jim VE3DDY

--- In BITX20@..., Arv Evans <arvevans@e...> wrote:
Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB, including
the
PTO/VFO, a Huff & Puff stabilizer, and three additional
transistors for T/R
power switching. It is a bit tight, but it can be done. Since
the RF stages
require shielding from the lower power sections, the use of
vertical sections
of blank PCB might allow parts of the circuit to be built on these
shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well if you
prefer that
method of construction. Some of the PCB layouts are documented in
the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several smaller
modules (about
1 inch by 2 inches) that were then assembled to make up a very
compact
layout.

By all means, read over the older email messages, then go to the
FILES and the
PHOTO sections and review what is there. You will find several
additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run into
problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._
On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into which I'd
like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller
configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


?Visit your group "BITX20" on the web.
?
?To unsubscribe from this group, send an email to:
?BITX20-unsubscribe@...
?
?Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.


Re: New to group and Query

Arv Evans
 

Jim VE3DDY

One of my BITX units is built on a 7 inch by 4 inch PCB, including the
PTO/VFO, a Huff & Puff stabilizer, and three additional transistors for T/R
power switching. It is a bit tight, but it can be done. Since the RF stages
require shielding from the lower power sections, the use of vertical sections
of blank PCB might allow parts of the circuit to be built on these shielding
partitions, thus allowing a more compact design.

PCBs have been designed and may still be available as well if you prefer that
method of construction. Some of the PCB layouts are documented in the FILES
and PHOTO sections of the forum.

Some BITX builders have constructed the unit in several smaller modules (about
1 inch by 2 inches) that were then assembled to make up a very compact
layout.

By all means, read over the older email messages, then go to the FILES and the
PHOTO sections and review what is there. You will find several additional
ideas for modification and upgrades.

Welcome aboard and good luck with your BITX. If you run into problems, there
are many now on the BITX forum that may be able to help.

Arv K7HKL
_._

On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into which I'd like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA modules.
I've lots of reading to catch up on.
Jim VE3DDY




YAHOO! GROUPS LINKS


?Visit your group "BITX20" on the web.
?
?To unsubscribe from this group, send an email to:
?BITX20-unsubscribe@...
?
?Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


New to group and Query

bambazonke01
 

Hi BIT-X'ers,
My name is Jim and I'm new to the group.
I'm a Canadian Radio Amateur and an avid experimenter.
I have an old Chinese type 884 VHF radio packset into which I'd like
to install a Bit-X perhaps for 40 Meters.
Has anyone reconfigured the main Bit-X PCB to a smaller configuration
approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller?
I also have similar size available for the VFO and PA modules.
I've lots of reading to catch up on.
Jim VE3DDY


Re: BITX in 2m band

ajparent1
 

Hello,

I have also done transverter for 2M in the past as well as 2m
RX designs.

A good filter for 2m can be done with 3 coils of helix design
using aperture (window) coupling. Constuction is a 3 cell box
using 2 sided copper clad board material.

I have also found it convenient to develope for VHF/UHF using
modular construction. For BITx this would be the audio,
modulator, carrier osilarot and IF stages on one board and
encased then later stages in boxed. Connections between boxes
is with coaxial cable for RF. The whole radio becomes a box
of boxes. This appears difficult but allows good shielding
and makes stage by stage testing easier.

Good luck with 2M.

FYI: I have tested early stages of the BITx for 6M without power
amplifers. With only 1mW (.001w) the range was only a few miles
but the signals sounded good at the other end and recieve performance
is as expected. More work is to build the power amplifier chain
and enclose it.

Allison
KB1GMX [FN42hh]

--- In BITX20@..., "eb7hpm" <msraya@t...> wrote:
--- In BITX20@..., Paolo Cravero as2594 <pcravero@a...>
wrote:
Hi
Great to read about your BITX developments!

I have one concern, though: will it be possibile to efficiently
filter
out unwanted harmonics +-n*10MHz at 144 MHz?

I think VHF&up transceivers use higher modulation IF or a
different
generation method.
Good... good question. ;-)
The Yaesu FT-290R have 4 passaband filters sintonized at 144MHz with
the aid of varicaps as output of mixer (it has also a ring diodes
mixer), it has a 11MHz FI, then I suposse this is not problem,
having some narrow passaband filters (four etapes minimun). The
consecuence of this is that the sintonization range will be narrow
also, but this is not a problem. I want to use only at 144.300 +-
50KHz. ;-) I do not use varicaps for sintonizing..

I make a tranverter for 28MHz to 144MHz a year ago and it also have
a 4 coil passaband filter little trickly to adjust. But no much
problem afterthat.

Howhever I not have made yet the tests. The 4 coil passaband filter
must be enclosed in a box, and the coupling must be soft. A coil
near the other coil assures soft coupling. It woks, as work for my
transverter a year ago.

Thank You for your coments.
Greetings
Manuel
EA7ARX


Just my thoughts,
Paolo IK1ZYW

--
| QRPp-I #707 + www.paolocravero.tk + I QRP #476 |
| SpamAssassin-based email antispam/antivirus solutions |
&#92; Italian/English-to/from-Croatian translations /
&#92; Skype: pcravero /


Re: BITX in 2m band

ajparent1
 

Hello,

Harmonics resulting from mixer operation are not a problem if
circuits are run linear with attention to correct signal levels.
Attention to filtering is a requirement and at 2M leads must be
short and use of shielding can be helpful.

I have a old and still very good Icom IC245 (nearly 30 years old)
2M CW/SSB/FM that the IF is 10.7mhz for SSB and CW.

However if the builder can use a 16 or 20mhz IF that is helpful.
It is possible to build a good SSB filter at 20mhz.


Allison
KB1GMX

--- In BITX20@..., Paolo Cravero as2594 <pcravero@a...> wrote:
Hi
Great to read about your BITX developments!

I have one concern, though: will it be possibile to efficiently filter
out unwanted harmonics +-n*10MHz at 144 MHz?

I think VHF&up transceivers use higher modulation IF or a different
generation method.

Just my thoughts,
Paolo IK1ZYW

--
| QRPp-I #707 + www.paolocravero.tk + I QRP #476 |
| SpamAssassin-based email antispam/antivirus solutions |
&#92; Italian/English-to/from-Croatian translations /
&#92; Skype: pcravero /


Re: BITX in 2m band

 

--- In BITX20@..., Paolo Cravero as2594 <pcravero@a...>
wrote:
Hi
Great to read about your BITX developments!

I have one concern, though: will it be possibile to efficiently
filter
out unwanted harmonics +-n*10MHz at 144 MHz?

I think VHF&up transceivers use higher modulation IF or a
different
generation method.
Good... good question. ;-)
The Yaesu FT-290R have 4 passaband filters sintonized at 144MHz with
the aid of varicaps as output of mixer (it has also a ring diodes
mixer), it has a 11MHz FI, then I suposse this is not problem,
having some narrow passaband filters (four etapes minimun). The
consecuence of this is that the sintonization range will be narrow
also, but this is not a problem. I want to use only at 144.300 +-
50KHz. ;-) I do not use varicaps for sintonizing..

I make a tranverter for 28MHz to 144MHz a year ago and it also have
a 4 coil passaband filter little trickly to adjust. But no much
problem afterthat.

Howhever I not have made yet the tests. The 4 coil passaband filter
must be enclosed in a box, and the coupling must be soft. A coil
near the other coil assures soft coupling. It woks, as work for my
transverter a year ago.

Thank You for your coments.
Greetings
Manuel
EA7ARX


Just my thoughts,
Paolo IK1ZYW

--
| QRPp-I #707 + www.paolocravero.tk + I QRP #476 |
| SpamAssassin-based email antispam/antivirus solutions |
&#92; Italian/English-to/from-Croatian translations /
&#92; Skype: pcravero /


Re: BITX in 2m band

Paolo Cravero as2594
 

Hi
Great to read about your BITX developments!

I have one concern, though: will it be possibile to efficiently filter out unwanted harmonics +-n*10MHz at 144 MHz?

I think VHF&up transceivers use higher modulation IF or a different generation method.

Just my thoughts,
Paolo IK1ZYW

--
| QRPp-I #707 + www.paolocravero.tk + I QRP #476 |
| SpamAssassin-based email antispam/antivirus solutions |
&#92; Italian/English-to/from-Croatian translations /
&#92; Skype: pcravero /


BITX in 2m band

 

Greetings to fellows BITX'ers.

The other day I was testing a VCO for the range of 144MHz with the
interest of making work the BITX in 2m. The VCO oscillates from 125
to 145MHz approximately with a air coil. I use 2N2222 transistors,
but I soon realized that the BFR90 worked quite better.

It is mounted using the "manhathan style", with a copper panel like
ground and "ugly" assembly.

Then, the PLL oscillator works perfectly without no modification to
this frequency, what doesn't stop surprising me. But, the stability
is poor due to the precarious assembly, however it is working
without problem.

The following step was to inject the 134MHz signal (I use a FI of
10MHz original) to the amplifier of the original VFO made of two
2N2222, the amplifier works and the circuit was able to transmit and
receive. However a output tank syntonized to 144MHz didn't exist in
this test, the signal was very weak.

Once installed a tank of 3 coils and an amplifier with a BFR90 I
succeeded in extracting the 144MHz signal, not without an adjustment
very critical and delicate. The BITX transmitted and received in 2m
USB!!

I could not have made more tests, neither place a front end
syntonized to 144MHz :-( . If the time permits me I follow
investigating, because the topic seems very promising.

I ham working in a multiband/multimode design
(80m/40m/20m/15m/10m/6m/2m) (AM/FM/SSB/CW). The idea is to carry out
three PCBs: SSB GENERATOR; PA, LPF, BPF; Microcontroller, PLL and
VCOs. The work possibly is never concluded for time problems, but at
least it could remain like contribution to whom he or she cheer up
to finish it. I put these schematics in the files section as soon I
can.

I like to ear coments to this developement.
Greetings
EA7ARX, ex EB7HPM/EC7ALV


35w 2 x irf 510 pa

 


Re: I am interested in EB7HPM PLL

 

Dear Manuel:
I want to be grateful to you for your courtesy in giving me the
information for the construction of the VFO and second for the advices
towards the group. In the weekend I will be constructing your project
and I will be notifying you of my experiences. The VFO that it uses for
the tests in the 40m band is a VACKAR that I extracted from a note of
the magazine CQ Spanish edition of the year 1994, which is extremely
stable and it gave me good satisfaction. The filter passband already
calculates it for the 11m band. As for the use of this band in our
country a rules exist at commercial level but it is not defined well at
keen level and consequently many people buy for u$s 30 a transceiver
and use it for personal ends. I belong to a tiny group that inside this
band (contaminated by the high power) devotes himself to the
experimentation and the activity DX with low power. From I am already
very grateful to you by the help. Cordial greetings for you and the
group. 73?s & DX from Argentina.
CARLOS MOSCA