heathkit hd 11 Q multiplier?

[kb2crk]

i was poking around ebay and came across quite a few of these. i did some reading and the concept sounds interesting. my question is is it worth while to pick one of these up for use with my HW 101 and if it is , how hard would it be to hook it up? at the price they are going for now i am almost tempted to get one just to put in the shack next to the 101...

[WØTKX]

I built a homebrew one, back in the day... but it wasn't for a Heathkit. They help a lot.


The Heathkit Q Multiplier was sold as an "add-on" upgrade super-duper accessory for Amateur HAM communications Receivers. Item was popular in the 1960's when most receivers used vacuum tubes. Many communications were done with CW or Morse code. Morse code is very bandwidth efficient and many signals could be heard at the same time.

The tube receivers did have filters but often the many signals were heard overlapping. The Q Multiplier could be added to any tube type receiver as an upgrade. It connected to the 455 kHz second IF with just the one coax. Q refers to the Quality of a circuit resonance. Resonance occurs when a signal matches the natural frequency of a circuit. The IF transformer is tuned to its operation frequency of 455 kHz plus or minus. Everything in that bandpass is heard in the headphones. By taking a small sample of the IF down the coax, amplifying it in the 12AX7 and returning it to the IF, the losses in the IF transformer would be overcome and the circuit Q "multiplied". One signal desired could be boosted out of the background. The Q Multiplier has a mode knob that allows this Peak operation. It also has a Notch mode where instead of returning an in-phase signal an out of phase signal was made. This reverse phase made a highly selective notch and could remove a strong local signal allowing a faint distant one to be heard.

The Q Multiplier has a tuning knob that lets the action be moved to the best place in the IF span. It has a gain knob to set the amount of boost or cut. Too much gain causes oscillation. To use the machine first turn it off and tune the signal desired on the regular receiver. Then leaving the main receiver tuning set, turn on the Q Multiplier and adjust to remove interference or boost desired signal. The Q Multiplier is for communications - it can cause distortion and hollow sounds like any narrow filter. With careful use can be helpful say with overseas 2-30 MHz HF broadcasts.

Q multipliers were also used by Single Side Band voice operators to cancel interference. There is no reason it could not be used with a transistor receiver but it would need a small tube type power supply since it normally stole power from the tube receiver supply. Also - in concept - you could change the 12AX7 to MOSFETs. Would need two as the tube had two triode sections to replace. Drop the B+ to say 15 VDC and upgrade the circuit for transistor receiver use.

[W5GA]

It would be even easier to get a radio with a real receiver in it. The HW-101 was several orders less than stellar. I'd be thinkin' Drake along about now if you want something that glows.

[WØTKX]

Well, yea. I'm very nostalgic about Heathkit myself, but I'll save it for the amplifiers.

[kb2crk]

sounds like it might be an option. now how hard is it to hook up? if i can snag one of these thing i may just go through it to make sure all is good and then put it to use.
i never owned a drake but have had several friends that have and i like the radios but the HW 101 has a place in my shack always. now if i could find a collins kwm2 cheap and i will be happy.

[W5GA]

now if i could find a collins kwm2 cheap and i will be happy.
Good luck with that...Collins and cheap are mutually exclusive.

[kb2crk]

Good luck with that...Collins and cheap are mutually exclusive.

i have noticed that lately. a lightning strike and subsequent shck fire left my kwm 2 a melted mess. that was 12 years ago and i still miss the thing. a hw101 is what i had for my first hf rig back in 87. that one was on 10 meters night and day.

[WØTKX]

Drakes... http://www.universal-radio.com/used/sold029.html

You can mod them and they will really perform.
Excellent RX, better than Heath or (gulp) Collins.

If you can "deal" with a hybrid radio, there are a lot more choices,
They still glow in the dark. Ask the bartender about his hybrid.

Check out this list: http://www.sherweng.com/table.html

[kb2crk]

i do like the drakes but i have never owned one. i am not against hybrids or any other radio for that matter. i do love the glow of the tube and the strage questions i get sometimes when i say what radio i am running. a kwm2 was my second hf rig and it was great. in a year and a half when my youngest child grduates high school i will have some extra cash to spend on radios. until then i have to skulk around looking for the deals.

[W1GUH]

I believe the HD-11 is the same as the QF-1 only with the PS built in. If that's that case, forget about it with an HW-101...you need a 455 (plus or minus) IF to use that Q-Multiplier (would've worked good with your KWM-2). Any receiver with a 455 kc IF will have greatly improved selectivity with a Q-Multiplier, and will also have that "null" option (like the Waters unit for S-Line).

Drake receivers better then Collins? I doubt it! :-P:neener::stickpoke:

But after I've managed to score a KWM-2 for the car (already have a DC supply!) and have done A/B testing with the TR-7, that opinion may change. The more I use the '7, the more I like it. That receiver is something wonderful!!!

[W5GA]

Drake receivers better then Collins? I doubt it! :-P:neener::stickpoke:
Yup, better. I can't remember the last time I saw a KWM-2 in competition, but the last time I saw that with a C-Line was 2 years ago.

[n2ize]

It would be even easier to get a radio with a real receiver in it. The HW-101 was several orders less than stellar. I'd be thinkin' Drake along about now if you want something that glows.

Could it be much worst than my old Lafayette HE-80 ? Actually the HE-80 is not a bad receiver. Great for 160 meter AM. Only problem is that it drifts like crazy. Even after it warms up it still has noticeable drift. But at the same time it is a nice looking receiver and its got tubes in it. And, i can't complain about the price. It was a NYC Sanitation Department special. Somebody threw it away and a friend who works in sanitation spotted it and set it aside for me.

[W1GUH]

Could it be much worst than my old Lafayette HE-80 ? Actually the HE-80 is not a bad receiver. Great for 160 meter AM. Only problem is that it drifts like crazy. Even after it warms up it still has noticeable drift. But at the same time it is a nice looking receiver and its got tubes in it. And, i can't complain about the price. It was a NYC Sanitation Department special. Somebody threw it away and a friend who works in sanitation spotted it and set it aside for me.

It's a pity the bedbugs have made sidewalk scores a no-no.

[n2ize]

It's a pity the bedbugs have made sidewalk scores a no-no.

Well, I dunno. If I see a good piece of radio gear sitting on the sidewalk a grab it.

[WØTKX]

http://www.sm0vpo.com:800/use/qmult.htm

[W1GUH]

Well, I dunno. If I see a good piece of radio gear sitting on the sidewalk a grab it.

Considering the expense and pita-ness, I"ll pass on anything. Now....if I had a supply of DDT..

[W1GUH]

http://www.sm0vpo.com:800/use/qmult.htm


...but for God's sake DO NOT TRY IT ON A VALVE RECEIVER!! The high voltages could be lethal.

Wuss!!!

One of life's mysteries for me is that, considering how cheap and simple a Q-Multiplier is, and how superb it is, both as a Peak and a Null device, why cheap crystal filters seemed to be so popular in lower mid-range receivers (SX-99, NC-109). A Q-Multiplier goes MUCH narrower than a simple crystal filter....and it's adjustable.

Made the AR-3 without peer amongst the 5 tube "converted BC receivers" like the S-38, et al.

[K5MIL]

It would be even easier to get a radio with a real receiver in it. The HW-101 was several orders less than stellar. I'd be thinkin' Drake along about now if you want something that glows.

When properly aligned the receiver in the HW-101 is as good as any of the receivers of the day and better than some. My HW-101 receives as well as my S-Line, KWM-2 and Drake 2-B. Don't sell it short.

http://radioremembered.org

[W5GA]

When properly aligned the receiver in the HW-101 is as good as any of the receivers of the day and better than some. My HW-101 receives as well as my S-Line, KWM-2 and Drake 2-B. Don't sell it short.

http://radioremembered.org
I think we have different uses for and different expectations from a receiver. I had a HW-101 for about 6 months back in the day. Going to a Drake B-Line was a breath of fresh air. I lean heavily towards the competition side of things.