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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

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 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.

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 .

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.

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.

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

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

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

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.

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




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---
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

--- In BITX20@..., "bambazonke01" <jimandruth@s...> wrote:
Hi,

Inline comments.

---
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.

It showed on my 20m on the bench as a hetrodyne with modulation. with
shielding it was less pronounced but I'm near Boston.

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.

Well if you get some 9.6mhz crystals as they are common and usually cheap.

Did you know that TEn Tec used to use CB crystals for their early
filters?

Yes, third overtone 27mhz. I've experimented with them and they
worked but not to my likeing.

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)

Yep, imaging transceivers were very popular. Crystals for 9mhz
ladder filters are easy to get as that is also another microporcessor
crystal. Another possible band image TRX is 30m and 17m using 4.0mhz
IF and 14mhz VFO.

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.

Cool. Over the years I've used every technique from the most
primitive to advanced CADD based with commercial expose, develope
and etch systems. Nice for n>1 runs but dead bug[ugly or manhattan]
is faster for one off.

I put a block diagram of a PLL I use for many uses in the FILES
section. I've reproduced it many times using different (but similar)
Pll chips.


Regards,
Allison
KB1GMX

.

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.

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Did I miss this attenuator? I am interrested to see the schematic (and
if someone build it, the results).
Thanks,
Chris.

Hello,

I have it on paper and in the chassis. It's still pending
getting it to an electronic form.

Basic design isa fairly stock PI form and uses 4 diodes
to attain about 40-45db of attenuation. Input and output
impedences are 50 ohms.

Allison