Fw: Re: [HBR] Radio design advice

[windy10605 at juno.com]

That's what I like about this group ....present some good ideas and come
away with better ideas. I had forgotten that I wanted to try a Pullen
mixer at the next opportunity and this is it. Also the use of Heathkit
HW/SBxxx parts of a junker (plenty out there) has been expanded. So where
I'm at now with the HetroGen-X :

1) Tuned preselector for 160/80/40/30m with plug-in coils, ceramic
socket, drop 80/40m band imaging in favor of 3995Khz IF 
2) 6" x 8" x 2" chassis, painted grey hammertone, decal, ........like
GB-1
3) HW/SBxxx 6AU6 Osc, 3" x 3-1/2", 36:1 tuning rate dual Jackson Bros
drives, sunk dial
4) 6SN7 Pullen Mixer, feeding ......
5) Heathkit 3995Khz Crystal SSB/CW filter, feeding......
6) 6S-?-7 fixed tuned 3995Kz regenerative detector (no BFO required, use
regen to compensate for the filter loss) 
7) 6SN7  for 2 stages of audio which should be good for headphones or a
small speaker.

Comments ? It's no HBR-xy but the idea is to make a really simple, but
effective, parts available today, tube receiver using octals (if you can)
to match the GB-1 Transmitter which uses a 6V6/6L6 on a 6x8x2 open
chassis.  

73 Kees K5BCQ



--------- Forwarded message ----------
From: N2EY at aol.com
To: hbr at mailman.qth.net
Date: Tue, 30 May 2006 21:00:50 EDT
Subject: Re: [HBR] Radio design advice
Message-ID: <3ba.2fb81d3.31ae44c2 at aol.com>

In a message dated 5/30/06 1:20:41 PM Eastern Daylight Time, 
windy10605 at juno.com writes:


> What I've come up with as the best alternative so far is something like
> the Simple-X receiver of the early 60s handbook using a tuned
preselector
> covering both 40/80m (pluggable coil), a  Heathkit HW/SBxxx VFO for
> tuning 5-5.5Mhz (36:1 vernier), both feeding a mixer with audio derived
> AVC ? Mixer output is a tuned 1843Khz IF coil with a 1843Khz crystal
> filter (cheap), driving a regenerative detector (no BFO required), and
> that drives 2 stages of audio. 
> 

6SL7 or 6SN7 Pullen mixer
6SL7 or 6SN7 oscillator/buffer a la W2YM, with Command set tuning cap
Xtal filter
6SK7 IF 
6SA7 product detector/BFO
6SL7 or 6SN7 audio (2 stages)

6J5 is equivalent to 1/2 6SN7. 6C5 may be close to 1/2 6SL7. 12 volt
heater 
tubes can be used as well.

If Pullen mixer is not wanted, use 6SA7 or 6SB7 pentagrid (6SB7
preferred). 
If W2YM VFO is not wanted, use 6SK7 in Hartley circuit.

The Heath LMO does not have a built-in vernier - the basic LMO module
takes 5 
turns to cover 500 kHz - way too fast. They're also not the easiest thing
to 
find without buying the whole rig, and you wind up with a lot of
metalwork.

The easiest way to use the ARC-5 tuning capacitor is to use it in a
cut-down 
transmitter chassis. There was an article in CQ called "A Low-Cost VFO"
by 
W2EWP that gives the mechanical details. The article also appears in the
"Command 
Sets" book which is free for the download from pmillet's site IIRC.

You need a BC-457 or BC-458, but only the VFO part and the tuning caps
need 
be intact.  

73 de Jim, N2EY
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