Hello. Im about 1/2 way through building the simple superhet rx in
doug demaws qrp notebook. (The brown covered one).
It uses a ca3028 mixer ic followed by a crystal filter and 1350 if
amps. Far Circuits sells a circuit board (which i purchased).
the main board is compact..about 4 inches by 3 inches.
Covers just one band..but you can use external converters to cover
other bands.
Let me know ..i could send you some info..jpg files i could scan.
Another good rcvr is the one in the ARRL handbooks ..it uses dual gate
mosfets ..I think its in the early 1990s handbooks.
73 Earl VE3AB

wrote in message ...
Hello. Im about 1/2 way through building the simple superhet rx in
doug demaws qrp notebook. (The brown covered one).
It uses a ca3028 mixer ic followed by a crystal filter and 1350 if
amps. Far Circuits sells a circuit board (which i purchased).
the main board is compact..about 4 inches by 3 inches.
Covers just one band..but you can use external converters to cover
other bands.
Let me know ..i could send you some info..jpg files i could scan.
Another good rcvr is the one in the ARRL handbooks ..it uses dual gate
mosfets ..I think its in the early 1990s handbooks.
73 Earl VE3AB

Hi Earl,
good luck with the project - not familiar with that one. One query -
can you or have you sourced the ic's - I think they are long obselete
(could be wrong) - its a worry with old designs.....
73 de VK3BFA Andrew

ps - currently building the Ashar Farhan BITX20 20m ssb transceiver -
a lovely design, absolute miminal implementation of a complex device.

....[snip]....
ps - currently building the Ashar Farhan BITX20 20m ssb transceiver -
a lovely design, absolute miminal implementation of a complex device.

Yes, a really-nice design, but I just received email from Ashar saying
that he was correcting (LM386 pins 5 and 6 are reversed, for example)
and updating (to make it more sensitive?) the BITX20 article in a few
days, so you might want to wait or contact him directly.

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

wrote in message ...
....[snip]....
ps - currently building the Ashar Farhan BITX20 20m ssb transceiver -
a lovely design, absolute miminal implementation of a complex device.

Yes, a really-nice design, but I just received email from Ashar saying
that he was correcting (LM386 pins 5 and 6 are reversed, for example)
and updating (to make it more sensitive?) the BITX20 article in a few
days, so you might want to wait or contact him directly.

--Myron.

Hi Myron,
yep, figured out the transposition on pins 5 and 6 of the LM386 - when
it wouldnt work! - took me a while to figure it out - a good fault
finding exercise!, and got the disused grey matter functioning again -
I honestly believe you learn very little from something that works
straight off, its when it doesnt you have to activate the (in my case
at least) long disused brain cells......

Have built the audio amp and the VFO - both working well. Am doing it
modular and troubleshooting each one as I go - next step is IF amps.
Did the audio amp "Manhattan" style using the NJQRP pad cutter and
wound up doing a PCB for the VFO - not being smart, just trying to
learn PROTEL pcb design at the same time hi hi.

Have corresponded with Ashar, he is making noises about a mailing list
for the BITX20 constructors - an excellent idea to share
ideas/disasters/general stuffing around/triumphs etc in the true
spirit of homebrew...(and, dare I say it, Amateur Radio)
73 de VK3BFA Andrew

wrote in message ...
....[snip]....
ps - currently building the Ashar Farhan BITX20 20m ssb transceiver -
a lovely design, absolute miminal implementation of a complex device.

Yes, a really-nice design, but I just received email from Ashar saying
that he was correcting (LM386 pins 5 and 6 are reversed, for example)
and updating (to make it more sensitive?) the BITX20 article in a few
days, so you might want to wait or contact him directly.

--Myron.

Hi Myron,
yep, figured out the transposition on pins 5 and 6 of the LM386 - when
it wouldnt work! - took me a while to figure it out - a good fault
finding exercise!, and got the disused grey matter functioning again -
I honestly believe you learn very little from something that works
straight off, its when it doesnt you have to activate the (in my case
at least) long disused brain cells......

Have built the audio amp and the VFO - both working well. Am doing it
modular and troubleshooting each one as I go - next step is IF amps.
Did the audio amp "Manhattan" style using the NJQRP pad cutter and
wound up doing a PCB for the VFO - not being smart, just trying to
learn PROTEL pcb design at the same time hi hi.

Have corresponded with Ashar, he is making noises about a mailing list
for the BITX20 constructors - an excellent idea to share
ideas/disasters/general stuffing around/triumphs etc in the true
spirit of homebrew...(and, dare I say it, Amateur Radio)
73 de VK3BFA Andrew

....[snip]....
ps - currently building the Ashar Farhan BITX20 20m ssb transceiver -
a lovely design, absolute miminal implementation of a complex device.

Yes, a really-nice design, but I just received email from Ashar saying
that he was correcting (LM386 pins 5 and 6 are reversed, for example)
and updating (to make it more sensitive?) the BITX20 article in a few
days, so you might want to wait or contact him directly.

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

wrote in message ...
Hello. Im about 1/2 way through building the simple superhet rx in
doug demaws qrp notebook. (The brown covered one).
It uses a ca3028 mixer ic followed by a crystal filter and 1350 if
amps. Far Circuits sells a circuit board (which i purchased).
the main board is compact..about 4 inches by 3 inches.
Covers just one band..but you can use external converters to cover
other bands.
Let me know ..i could send you some info..jpg files i could scan.
Another good rcvr is the one in the ARRL handbooks ..it uses dual gate
mosfets ..I think its in the early 1990s handbooks.
73 Earl VE3AB

Hi Earl,
good luck with the project - not familiar with that one. One query -
can you or have you sourced the ic's - I think they are long obselete
(could be wrong) - its a worry with old designs.....
73 de VK3BFA Andrew

ps - currently building the Ashar Farhan BITX20 20m ssb transceiver -
a lovely design, absolute miminal implementation of a complex device.