[HBR] Product Detector

[Dan Merz]

Hi again,  I looked thru my pile of 390a mod's,  past articles,  etc and
found no tubed external PD projects, or circuits for the agc in an external
unit.  I did find Lee's original article on the internal PD mod using the
bfo socket for a 6BE6 PD but you are probably familiar with that.  If you
use the HBR circuitry,  you might want to consider a version of agc used in
the 67/68 17th edition Radio Handbook Deluxe HBR Receiver,  which is more
elaborate than the "standard" HBR circuit.  I have no experience with it so
can't vouch for it... Just a thought.  It's a hang circuit designed for
ssb/cw with fast attack and selectable release,  uses 3-triode 6BC7 and
12au7,  best regards,  Dan.   

-----Original Message-----
From: hbr-bounces at mailman.qth.net [mailto:hbr-bounces at mailman.qth.net] On
Behalf Of DW Holtman
Sent: Saturday, January 21, 2006 8:36 PM
To: hbr at mailman.qth.net
Subject: [HBR] Product Detector

Hello,

I have a question that I hope that someone can help me with.  I'm looking to
build a Product Detector for a R-390A receiver. The R-390A has a BNC
connector on the back with the If of 455 KHZ coming out. What I want to do
is build a quality detector in a chassis that will mount in a standard 19
inch rack. The mechanics I can handle. What I'm looking for specifically is

1.  Tube gear.
2. Built in AGC circuit, with at least 2 time constants, ie; fast and slow
as well as MGC using manual RF attenuation (pot).
3. At least 2 maybe as much as 4 If stages for better selectivity.
4. Don't know yet is it is better to use cans or crystal/mechanical filters.
5. Don't need a high power audio amp, will feed audio back onto the R-390A
and use the onboard audio amp.

What I'm looking for is a construction project from an old ARRL handbook or
QST article for a quality receiver. I will only use the If strip and the
detector and low power audio amp. If anyone has any suggestions on what year
handbook/'QST might have something promising, please let me know.

Thank you in advance for any information.

73's
DW Holtman
WB7SSN




************************************
Visit the HBR Receiver Web Site with over 100 pictures of receivers and
construction notes...... via http://www.qsl.net/k5bcq/ there is also a
mirror (faster response)at http://k5bcq.edebris.com/
 

Retrieve reflector archived data via
http://mailman.qth.net/mailman/listinfo/hbr