[Hammarlund] HQ-129X - more. Product Detector

[D C _Mac_ Macdonald]

Back around 1964 or so, I lifted the circuitry for the product detector of the National NCX-3 AND its fast attack-slow decay AGC and installed them both in my almost new (1961) HQ-145X receiver.  Both worked extremely well all the way to 10 meters!

73 de Mac, K2GKK/5​
Since 30 Nov 1953​
Oklahoma City, OK​
USAF, Retired ('61-'81)​
FAA, Retired ('94-'10)

________________________________
From: hammarlund-bounces at mailman.qth.net <hammarlund-bounces at mailman.qth.net> on behalf of Ken <kgordon2006 at frontier.com>
Sent: Thursday, May 30, 2019 10:17
To: Mark Dinsmore
Cc: Hammarlund at mailman.qth.net
Subject: Re: [Hammarlund] HQ-129X - more. Product Detector

Yes. I most certainly can, but I'll have to wait until I can get to my computer.Standby.Ken W7EKBSent via my Samsung Galaxy, an AT&T 4G LTE smartphone
-------- Original message --------From: Mark Dinsmore <markdinsmore at gmail.com> Date: 5/29/19  22:10  (GMT-08:00) To: "Kenneth G. Gordon" <kgordon2006 at frontier.com> Cc: Hammarlund at mailman.qth.net Subject: Re: [Hammarlund] HQ-129X - more. Product Detector Hi Ken. I would like to create an external product detector for my HQ-150. I assume it would be similar to what you would create for the 129x. Can you recommend a good place, resources to get started?Mark K7MDSent from my iPhone> On May 29, 2019, at 1:05 PM, Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:> > Another upgrade I intend to do to my own HQ-129X is the install a real product-detector.> > When I did this many years ago to my BC-779, I was amazed at how much quieter and > apparently more sensitive that receiver became. It literally blew me away at how much > better the receiver worked.> > I used the circuit which Heathkit uses in their SB rigs, a single-triode unit, which, it also > turned out, demodulates AM just
  fine too with the BFO off.> > At that point, I became a very firm believer in upgrading our older receivers with a D > PD.
> > Ken W7EKB>