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Thread: heathkit hd 11 Q multiplier?

  1. #1
    Lord of the Flies kb2crk's Avatar
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    heathkit hd 11 Q multiplier?

    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...


    a yankee living in the hind end of the bible belt
    some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.

  2. #2
    Whacker Knot WØTKX's Avatar
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    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.
    "Where would we be without the agitators of the world to attach the electrodes
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  3. #3
    Conch Master W5GA's Avatar
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    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 the government's boot is on your throat, whether it is a left boot or a right boot is of no consequence. — GARY LLOYD

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  4. #4
    Whacker Knot WØTKX's Avatar
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    Well, yea. I'm very nostalgic about Heathkit myself, but I'll save it for the amplifiers.
    "Where would we be without the agitators of the world to attach the electrodes
    of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman



  5. #5
    Lord of the Flies kb2crk's Avatar
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    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.


    a yankee living in the hind end of the bible belt
    some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.

  6. #6
    Conch Master W5GA's Avatar
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    Quote Originally Posted by kb2crk View Post
    now if i could find a collins kwm2 cheap and i will be happy.
    Good luck with that...Collins and cheap are mutually exclusive.
    When the government's boot is on your throat, whether it is a left boot or a right boot is of no consequence. — GARY LLOYD

    The nation we live in is the nation we have built by design, each successive generation raising the wall of tyranny a little higher. - Chris Griffin

  7. #7
    Lord of the Flies kb2crk's Avatar
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    Quote Originally Posted by W5GA View Post
    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.


    a yankee living in the hind end of the bible belt
    some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.

  8. #8
    Whacker Knot WØTKX's Avatar
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    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
    Last edited by WØTKX; 12-29-2010 at 12:12 AM.
    "Where would we be without the agitators of the world to attach the electrodes
    of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman



  9. #9
    Lord of the Flies kb2crk's Avatar
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    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.


    a yankee living in the hind end of the bible belt
    some people are like slinkys, not really good for anything, but still bring a smile to your face when you push them down the stairs.

  10. #10
    Silent Key Member 5-25-2015 W1GUH's Avatar
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    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: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!!!
    If it's a war on drugs, then free the POW's.

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