开云体育

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.

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

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

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

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

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.

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.

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 .

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.

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
_._

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

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]

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.

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

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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

--
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| SpamAssassin-based email antispam/antivirus solutions |
&#92; Italian/English-to/from-Croatian translations /
&#92; Skype: pcravero /

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

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

I'm Sorry Carlos, but the group's language is English. You may
prioritary to post in english. The mayority of others members only
understand english. Good, You must compose the message in lowercase
also, please. I can translate your question to english:

"Dear Manuel:

To conclude the construction of BITX I have a problem: to find a vfo
circuit that was stable to high frecuency. Initially the xcver was
adjusted in the 40m band only for testing purposes, but I don't have
ham radio license yet and I could not operate it. I have interest to
convert it to the 11meter band, in which i operate provisionally
until I get the license. I encounter interesting your circuit, for
that reason I ask for schematic of your VFO circuit used. I ned to
cover 27.400 to 27.900. The VFO is working from 17.4 to 17.9 or 37.4
to 37.9.

Another question is how to modify the program in order to cover this
frecuencies that show in the display. I be apreciated for you. In
principly I was thinking to build a DDS VFO, but the expense for
single band operation was not justified.

Perhaps when I have a license I face a multiband project with DDS.
Thank You and Greetings from Argentina.

73's and DX. CARLOS EDUARDO MOSCA"

I reply first shortly in English first, then in spanish.

Carlos, el lenguaje del grupo es Inglés, por favor postea solo en
Ingles si te es posible, pues los demás miembros del foro no te van
a entender. También es normal postear en minusculas, hacerlo en
mayusculas no está bien visto. Respondo de forma breve a tus
preguntas:

-> The VFO is the same of BITX, I change de emiter-base and emiter-
groud capacitor to 47pF value for 31MHz operation. I change the coil
for a 1uH to resonate at 30MHz. This oscilator can work to 50MHz
aprox. I put a AM varicap(high capacity) in series with 1nF
capacitor to the oscilator coil. I put a 100K resistor from varicap
to PLL output. I put a 39pF capacitor from emiter oscilator to PLL
input.

-> You can change the frecuency of BITX to 27 MHz, only changing the
oscilator coil and the BPF filter coils and capacitors. But you must
test if the 11meters operation with modified equipement in your
country is legal. In my country this is not legal.

-> The software don't have to be modified. It works from 0 to 180MHz
unmodified, you only must to supply a apropiate VFO that got this
frecuency.

73's and good luck.
EA7ARX, ex EB7HPM/EC7ALV

This in spanish:
-> El VFO es el mismo que el del BITX, He cambiado el condensador
que va del emisor a la base y del emisor a tierra por 47pF. He
cambiado la bobina por un bote sintonizable de alrededor de 1
microhenrio para que resuene en 30MHz. Esta configuración del
oscilador puede funcionar sin problemas hasta unos 50MHz. Puse un
varicap de AM(alta capacidad) en serie con un condensador de 1nF
conectado a la bobina osciladora del VFO. Puse una resistencia de
100K desde el varicap a la salida del PLL. Puse un condensador de
39pF del emisor del transistor oscilador a la entrada del PLL,
usando cable coaxial.

-> Puedes cambiar la frecuencia del BITX a 27 MHz, tan solo
cambiando la bobina del oscilador y las bobinas y condensadores del
filtro pasobanda de la entrada. Pero debes asegurarte que puedes
transmitir en 11 metros con equipos modificados en tu pais de forma
legal, en mi pais no es legal.

-> El software no es necesario modificarlo. Funciona desde 0 a 180
MHz sin problema, solo debes colocar un VFO apropiado que llege a
esa frecuencia.

73's y buena suerte.
EA7ARX, ex EB7HPM/EC7ALV

ESTIMADO MANUEL:

AL FINALIZAR CON EXITO LA CONSTRUCCION DEL BITX ME ENCONTRE CON LA
DIFICULTAD DE HALLAR UN CIRCUITO VFO QUE SEA ESTABLE A ALTA FRECUENCIA.
INICIALMENTE EL XCVER LO AJUSTE EN LA BANDA DE 40M A MODO DE PRUEBA,
PERO EL INCONVENIENTE ES QUE AL NO POSEER LICENCIA NO PUEDO OPERARLO EN
BANDAS DE AFICIONADOS. MI INTERES ES PASARLO A LA BANDA DE 11M; BANDA
EN LA QUE OPERO MOMENTANEAMENTE HASTA QUE CONSIGA LA DISTINTIVA.
ENCONTRE INTERESANTE TU CIRCUITO, POR ESO TE PEDIRIA SI POR FAVOR ME
PUEDES PASAR UN COPIA DEL CIRCUITO VCO QUE UTILIZASTE. YO NECESITO
CUBRIR DE 27.400Khz A 27.900Mhz O SEA QUE EL VCO LO HARIA TRABAJAR DE
17.4 A 17.9Mhz O 37.4Mhz A 37.9Mhz. OTRA CUESTION ES QUE PARTES DEL
PROGRAMA TENGO QUE VARIAR PARA TENER ESTA COBERTURA Y A LA VEZ QUE ME
LA MUESTRE EN EL DISPLAY.
TE ESTARIA ETERNAMENTE AGRADECIDO POR EL FAVOR; EN UN PRINCIPIO IBA A
CONTRUIR UN VFO DDS PERO NO SE JUSTIFICABA EL GASTO PARA UNA SOLA BANDA.
QUIZAS PARA CUANDO TENGA LA LICENCIA ENCAREMOS UN PROYECTO MULTIBANDA
CON DDS. DESDE YA MUCHAS GRACIAS Y SALUDOS CORDIALES DESDE ARGENTINA.

73?s & DX. CARLOS EDUARDO MOSCA

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