Hi Arv,
I'm thinking of building a 40m version of the BITX20. As Ashhar
mentions in one of his earlier mails, that is the band more popular
here in India.
Could you please guide me on the different stages of the circuit you
modified and the nature of changes you made?
Also, may I please have a copy of the gif file of the discreet
components AF Amplifier?
Thanks in advance.
73s,
Bharat, VU2BDX
--- In BITX20@..., arvevans@e... wrote:
Hello to the BITX20 group (this is my first posting on this forum).
Farhan and myself have exchanged a couple of off-forum emails
regarding mods to his excellent design. One interesting possibility
is replacement of the LM-386 with a discrete component AF Amplifier.
He said that he had not had the time to work up a schematic...so I
have provided one (see attached .gif file). This can allow those
without access to an LM-386 to build the unit.
Also, my layout for the BITX20 uses 10.7 MHZ IF transformers
salvaged from dead AM/FM radios ( I dislike winding toroids! ). My
construction is a BITX40 (40 Meters) and requires 55 pf across the
10.7 IFs to resonate on 7.2 MHZ. These 10.7 IF transformers might be
made to resonate on 20M if the internal capacitors were removed (
break them with a screwdriver point ) and a small variable ( 5-25pf )
used to bring them to resonance.
73's
Arv - K7HKL
