Date   
hi everybody

satyan <gladsarul@...>
 

i am satyan from chennai,india. i am expcting my ticket soon and is
interested in getting a rig for 20 mtrs ssb/qrp. i have heard about
bitx20 txcvr and would like to know if anybody can enlighten me on the
availablity of kits/assembled and tested rigs in inida. any
information will be highly appreciated

73s

BITX40

py2ha
 

 

 

Hello Fahran....

 

Good morning...

I am mounting the BITX it will be 40 meters and I found an error in the diagram of the amplifier of audio with LM386N1, bolts 5 and 6 are inverted.

 

Please confirms....

 

73 of Luis PY2HA

 

 




Re: BITX40

Steve Hartley G0FUW <g0fuw@...>
 

I belive this point has been raised before - try searching on achive messages.
Good luck with BITX 40.
73, Steve, G0FUW

----- Original Message -----
From: py2ha
Sent: Sunday, January 29, 2006 7:36 AM
Subject: [BITX20] BITX40

 

 

Hello Fahran....

 

Good morning...

I am mounting the BITX it will be 40 meters and I found an error in the diagram of the amplifier of audio with LM386N1, bolts 5 and 6 are inverted.

 

Please confirms....

 

73 of Luis PY2HA

 

 




RES: BITX40

py2ha
 

Hello Steve.... 

Thanks will be to answer.... 

I found the reply in messages 87 and 89.... 

73 of Luis PY2HA

 

Visite my site

http://geocities.yahoo.com.br/py2ha

 

 

 


De: BITX20@... [mailto:BITX20@...] Em nome de Steve Hartley G0FUW
Enviada em: domingo, 29 de janeiro de 2006 17:37
Para: BITX20@...
Assunto: Re: [BITX20] BITX40

 

I belive this point has been raised before - try searching on achive messages.

Good luck with BITX 40.

73, Steve, G0FUW

----- Original Message -----

From: py2ha

Sent: Sunday, January 29, 2006 7:36 AM

Subject: [BITX20] BITX40

 

 

 

 

 

Hello Fahran....

 

Good morning...

I am mounting the BITX it will be 40 meters and I found an error in the diagram of the amplifier of audio with LM386N1, bolts 5 and 6 are inverted.

 

Please confirms....

 

73 of Luis PY2HA

 

 





Where to start?

Dirk F Ganzinga
 

Hi, this looks like a nice project, but I can't seem to find the take
off point. There are several pcb-layouts, lots of mods, etc. Can anyone
indicate a safe route through all files and data overhere? My goal is
to build a 20m transceiver, non-Manhattan style, PTT and possibly
digital display later.
Kind regards,
Dirk

Re: Where to start?

Pete Morris <egnaro937@...>
 

Hi, Dirk,
 
I started by building the RF filter, PA and pi-filter. I then cobbled-together a DSB exciter to test it with, and stopped there.
 
I hope to build a complete BITX20 sometime soon, but until then, by little DSB jobbie (vxo tuning 14295-14315) is just too much fun...
 
Pete G1INF, G-QRP 11768
Worthing, UK  Loc. IO90TT

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf Of Dirk F Ganzinga
Sent: 01 February 2006 21:51
To: BITX20@...
Subject: [BITX20] Where to start?

Hi, this looks like a nice project, but I can't seem to find the take
off point. There are several pcb-layouts, lots of mods, etc. Can anyone
indicate a safe route through all files and data overhere? My goal is
to build a 20m transceiver, non-Manhattan style, PTT and possibly
digital display later.
Kind regards,
Dirk



Re: Where to start?

Rahul Srivastava
 

Hi!
 
You need to make both the Rx as well as TX side simultaneously. I suggest start with audio section ie af preamp and mic amp and the BFO / PD. This will give you sufficient working stages for DSB alone .
BFO will yield a working OSC for further XTAL freq measurement in order to match for filter.
Later on add the IF stages filter and front end, vfo for final completion.
 
Hope this helps
 
Good luck & 73
 
Rahul VU3WJM
 
PS: If you want to take the PCB route I have uploaded one under files.
 
 


Dirk F Ganzinga wrote:
Hi, this looks like a nice project, but I can't seem to find the take
off point. There are several pcb-layouts, lots of mods, etc. Can anyone
indicate a safe route through all files and data overhere? My goal is
to build a 20m transceiver, non-Manhattan style, PTT and possibly
digital display later.
Kind regards,
Dirk





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Bitx20

Jamie
 

Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ

Re: Bitx20

Vakarcs Szil�rd
 

tv baluns are no longer available, because the modern tv rigs have an 75 ohm output impedance instead of 300. You have to search hamradio stores where you find the so called material of 43,  37-43 or so, you can use two rings for binocular or 1 pieces of 7X14 mm binocular material.

Jamie wrote:
Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ






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Re: Bitx20

Pete Morris <egnaro937@...>
 

Hi, Jamie,
 
The schematic at http://www.phonestack.com/farhan/bitx.html is probably the current one. It has values for all non-broadband inductors, so you can wind them (or purchase) to your own taste. I used toroids for my pi-filter, and intend to use rewound IF canned coils for my preselector (currently uses axial chokes - yuck!).
 
The (TV) balun cores are obtainable from www.jaycarelectronics.com or from RS Components subsidiaries, your local would be http://www.electrocomponents.com/countries/canada.htm 
 
Good luck!
 
Pete G1INF, G-QRP 11768
Worthing, UK  Loc. IO90TT

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf Of Jamie
Sent: 19 February 2006 03:01
To: BITX20@...
Subject: [BITX20] Bitx20

Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ




Re: Bitx20

Jamie
 

Vakarcs

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf Of Vakarcs Szilárd
Sent: Sunday, February 19, 2006 5:24 AM
To: BITX20@...
Subject: Re: [BITX20] Bitx20

tv baluns are no longer available, because the modern tv rigs have an 75 ohm output impedance instead of 300. You have to search hamradio stores where you find the so called material of 43,  37-43 or so, you can use two rings for binocular or 1 pieces of 7X14 mm binocular material.

Jamie wrote:
Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ






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Re: Bitx20

Jamie
 

Thank you Pete and Vacarcs for the information, I will go with toroids and the 2004 schematic.
 
73  Jamie/VE3GXQ

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf Of Vakarcs Szilárd
Sent: Sunday, February 19, 2006 5:24 AM
To: BITX20@...
Subject: Re: [BITX20] Bitx20

tv baluns are no longer available, because the modern tv rigs have an 75 ohm output impedance instead of 300. You have to search hamradio stores where you find the so called material of 43,  37-43 or so, you can use two rings for binocular or 1 pieces of 7X14 mm binocular material.

Jamie wrote:
Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ






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Re: Bitx20

Arv Evans
 

Jamie

For my BITX40 I used a conventional one-core balun in place of the binocular core unit.  This was wound transmission-line style where the wires were twisted together before winding.  Since this balun is broad-banded, the primary concern is to obtain proper impedance transformation. 

Information on designing your own balun transformer can be found at many locations on the Internet.  Here are a few places to start looking:
http://www.oselectronics.com/downloads/Broadband%20Transformers.pdf
http://radioworks.com/nbalun.html
http://www.w8ji.com/core_selection.htm
One of the attractive things about the BITX design is that it can be modified to fit the parts that you either have available or can obtain at little cost. 

Arv
_._


Vakarcs Szilárd wrote:
tv baluns are no longer available, because the modern tv rigs have an 75 ohm output impedance instead of 300. You have to search hamradio stores where you find the so called material of 43,  37-43 or so, you can use two rings for binocular or 1 pieces of 7X14 mm binocular material.

Jamie wrote:
Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ






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Re: Bitx20

Jamie
 

Arv:
 
Thank you for the information and links I will do a little more reading and then just jump in. I assume the coils are used to join/couple the various stages?
 
Jamie

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf Of Arv Evans
Sent: Sunday, February 19, 2006 12:52 PM
To: BITX20@...
Subject: Re: [BITX20] Bitx20

Jamie

For my BITX40 I used a conventional one-core balun in place of the binocular core unit.  This was wound transmission-line style where the wires were twisted together before winding.  Since this balun is broad-banded, the primary concern is to obtain proper impedance transformation. 

Information on designing your own balun transformer can be found at many locations on the Internet.  Here are a few places to start looking:
http://www.oselectronics.com/downloads/Broadband%20Transformers.pdf
http://radioworks.com/nbalun.html
http://www.w8ji.com/core_selection.htm
One of the attractive things about the BITX design is that it can be modified to fit the parts that you either have available or can obtain at little cost. 

Arv
_._


Vakarcs Szilárd wrote:
tv baluns are no longer available, because the modern tv rigs have an 75 ohm output impedance instead of 300. You have to search hamradio stores where you find the so called material of 43,  37-43 or so, you can use two rings for binocular or 1 pieces of 7X14 mm binocular material.

Jamie wrote:
Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ






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Re: Bitx20

Rahul Srivastava
 

HI!
 
Single hole cores or beads would work fine. Farhan on his blog  shows a prototype using only one hole of binoculor core,  chiping the other.
 
 
I  know a person who used T-10 torroids salvaged from defunt cheap CFL lamps.
 
Adaptable design indeed.
 
73
 
Rahul VU3WJM 

Arv Evans wrote:
Jamie

For my BITX40 I used a conventional one-core balun in place of the binocular core unit.  This was wound transmission-line style where the wires were twisted together before winding.  Since this balun is broad-banded, the primary concern is to obtain proper impedance transformation. 

Information on designing your own balun transformer can be found at many locations on the Internet.  Here are a few places to start looking:
http://www.oselectronics.com/downloads/Broadband%20Transformers.pdf
http://radioworks.com/nbalun.html
http://www.w8ji.com/core_selection.htm
One of the attractive things about the BITX design is that it can be modified to fit the parts that you either have available or can obtain at little cost. 

Arv
_._


Vakarcs Szil�rd wrote:
tv baluns are no longer available, because the modern tv rigs have an 75 ohm output impedance instead of 300. You have to search hamradio stores where you find the so called material of 43,  37-43 or so, you can use two rings for binocular or 1 pieces of 7X14 mm binocular material.

Jamie wrote:
Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ






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Re: Bitx20

sg2112 <SG2112@...>
 

You can also use a 2N5109, 2SC1252, and 2SC1253 ... Dan's Small Parts
have the 2SC1253 for US $1.50, the 2N3866 for $2.50 and the 2N5109 for
$2.85 ... I used a pair of 2SC1253's in place of 2N5109's in a Norton
Noiseless Feedback push pull RF preamp and they worked great ... they
are actually better than the 2N3866, but can't handle quite as much
current as a 2N5109 (Not a problem in this case) ... I'd go with the
2SC1253, they are cheaper and will drop right into the circuits

Dan's also has some 2 hole balun cores as well as the standard ferrite
toroid cores, in fact I got some #43 balun cores s couple of months
back for 10/1.00 on a close out deal he had which I plan to use with
this very project in mind

JR

--- In BITX20@..., "Jamie" <jamie@...> wrote:

Hello everyone:

Now that winter has really set in I am ready to begin my BITX project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and now
totally confused as to which schematic to follow. I am going to build
it manhattan style (my son and I have built a regenerative receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The 2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another question is
where do I get TV balun cores? Should I look for a TV that is being
scrapped or can I buy them new? The electronics stores that I go to
don't seem to have them. Perhaps a TV repair shop may be able to get
me some? Does anyone have values for the coils? I would like to wind
them on toroids if I can't get the TV baluns. Thank you for reading
this, 73 and good DX.

Jamie/VE3GXQ

Re: Bitx20

Chris van den Berg
 

i am affraid I do not understand this discussion. the 2N3866 is not
mentioned in the schematic of the BITX,. I think what is discussed
has to do with an other design by Farhan.
Chris.

--- In BITX20@..., "sg2112" <SG2112@...> wrote:

You can also use a 2N5109, 2SC1252, and 2SC1253 ... Dan's Small
Parts
have the 2SC1253 for US $1.50, the 2N3866 for $2.50 and the 2N5109
for
$2.85 ... I used a pair of 2SC1253's in place of 2N5109's in a
Norton
Noiseless Feedback push pull RF preamp and they worked great ...
they
are actually better than the 2N3866, but can't handle quite as much
current as a 2N5109 (Not a problem in this case) ... I'd go with
the
2SC1253, they are cheaper and will drop right into the circuits

Dan's also has some 2 hole balun cores as well as the standard
ferrite
toroid cores, in fact I got some #43 balun cores s couple of months
back for 10/1.00 on a close out deal he had which I plan to use
with
this very project in mind

JR

--- In BITX20@..., "Jamie" <jamie@> wrote:

Hello everyone:

Now that winter has really set in I am ready to begin my BITX
project.
I have been a ham for over 25 years but am kind of new to the
homebuild thing.I have read everything in the newsgroup and and
now
totally confused as to which schematic to follow. I am going to
build
it manhattan style (my son and I have built a regenerative
receiver
that way and it works well) and I need some direction. The two
schematics that I found are dated 2003 and the other 2004. The
2003
schematic uses mostly 2n3866's and the 2004 uses BF195's. Does
anyone
have an opinion? I intend to build the 20m version for
backpack/camping use and simple is better overall. Another
question is
where do I get TV balun cores? Should I look for a TV that is
being
scrapped or can I buy them new? The electronics stores that I go
to
don't seem to have them. Perhaps a TV repair shop may be able to
get
me some? Does anyone have values for the coils? I would like to
wind
them on toroids if I can't get the TV baluns. Thank you for
reading
this, 73 and good DX.

Jamie/VE3GXQ

Re: Bitx20

Jamie
 

Chris:
 
I have found 2 BITX designs. One with a schematic date of 2003 and one with a schematic date of 2004. The diagrams and componenets are similar however there are some major differences. I was just tryinmg to clarify which design most people are building and having success with.
 
Jamie/VE3GXQ

-----Original Message-----
From: BITX20@... [mailto:BITX20@...] On Behalf Of vdberghak
Sent: Tuesday, February 21, 2006 11:04 AM
To: BITX20@...
Subject: [BITX20] Re: Bitx20

i am affraid I do not understand this discussion. the 2N3866 is not
mentioned in the schematic of the BITX,. I think what is discussed
has to do with an other design by Farhan.
Chris.

--- In BITX20@..., "sg2112" wrote:
>
> You can also use a 2N5109, 2SC1252, and 2SC1253 ... Dan's Small
Parts
> have the 2SC1253 for US $1.50, the 2N3866 for $2.50 and the 2N5109
for
> $2.85 ... I used a pair of 2SC1253's in place of 2N5109's in a
Norton
> Noiseless Feedback push pull RF preamp and they worked great ...
they
> are actually better than the 2N3866, but can't handle quite as much
> current as a 2N5109 (Not a problem in this case) ... I'd go with
the
> 2SC1253, they are cheaper and will drop right into the circuits
>
> Dan's also has some 2 hole balun cores as well as the standard
ferrite
> toroid cores, in fact I got some #43 balun cores s couple of months
> back for 10/1.00 on a close out deal he had which I plan to use
with
> this very project in mind
>
> JR
>
> --- In BITX20@..., "Jamie" <jamie@> wrote:
> >
> > Hello everyone:
> >
> > Now that winter has really set in I am ready to begin my BITX
project.
> > I have been a ham for over 25 years but am kind of new to the
> > homebuild thing.I have read everything in the newsgroup and and
now
> > totally confused as to which schematic to follow. I am going to
build
> > it manhattan style (my son and I have built a regenerative
receiver
> > that way and it works well) and I need some direction. The two
> > schematics that I found are dated 2003 and the other 2004. The
2003
> > schematic uses mostly 2n3866's and the 2004 uses BF195's. Does
anyone
> > have an opinion? I intend to build the 20m version for
> > backpack/camping use and simple is better overall. Another
question is
> > where do I get TV balun cores? Should I look for a TV that is
being
> > scrapped or can I buy them new? The electronics stores that I go
to
> > don't seem to have them. Perhaps a TV repair shop may be able to
get
> > me some? Does anyone have values for the coils? I would like to
wind
> > them on toroids if I can't get the TV baluns. Thank you for
reading
> > this, 73 and good DX.
> >
> > Jamie/VE3GXQ
> >
>




USB & LSB in two-band rig

bill_noyce <WBNoyce@...>
 

Sometime this year I intend to build a BITX, and have
been thinking about making it a two-band rig, for 40
and 17 meters. I had been thinking to model it on the
"classic" 80 & 20 meter transceivers we've read about,
where a 9 MHz IF and 5.2 MHz VFO gives 3.8 MHz LSB or
14.2 MHz USB. Or does it?

As I work through the mixing scheme, it seems to me
that if the IF signal is USB, then so is the result
after mixing. Say there are pure tones at 400 and 500
Hz above 9 MHz. Then adding 5.2 MHz gives 14.200400 and
14.200500, clearly USB as expected. But subtracting
5.2 MHz instead gives 3.800400 and 3.800500, also USB.

It seems to me the "classic" scheme only works if the
*VFO* is around 9 MHz, and the *IF* is around 5.2 MHz.
Then the IF gets subtracted from the VFO, so its
sideband is reversed, as we wish.

The only problems with this are that, if I recall, it's
a little difficult to build a nice SSB filter at the
lower IF frequency. I'll have to go look that up again...
And it's also tough to get a stable VFO at 9 MHz.

To use this scheme for 40 & 17 meters, I would need the
IF to be around 5.5 MHz, and the VFO around 12.7 MHz.
Gee, it seemed a lot more feasible the other way around.

I guess the alternative is to use 12.7 for the IF and
5.5 for the VFO, and switch sidebands by offsetting
the BFO. Unless someone can show where I've made a
mistake in this analysis. How *did* those old 80/20
rigs work?

-- Bill, AB1AV

Re: Bitx20

bill_noyce <WBNoyce@...>
 

--- In BITX20@..., "Jamie Holmes" <jamie@...> wrote:

I have found 2 BITX designs. One with a schematic date of 2003 and one
with a schematic date of 2004.
Jamie - I'm pretty sure the 2003 design you found is Ashar's
"Simple SSB Transceiver" -- it doesn't use bidirectional amps,
but instead has relay switching to reuse the crystal filter
in transmit and receive, as well as to switch bands.

The 2004 schematic is the BITX, and Q1/Q13, Q2/Q12, and Q3/Q11
form the bidirectional amplifiers.

-- Bill, AB1AV