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.
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
of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman
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
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
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.Originally Posted by W5GA
Last edited by n2ize; 01-07-2011 at 07:38 AM.
I keep my 2 feet on the ground, and my head in the twilight zone.
It's a pity the bedbugs have made sidewalk scores a no-no.
If it's a war on drugs, then free the POW's.
Well, I dunno. If I see a good piece of radio gear sitting on the sidewalk a grab it.
I keep my 2 feet on the ground, and my head in the twilight zone.
Considering the expense and pita-ness, I"ll pass on anything. Now....if I had a supply of DDT..
If it's a war on drugs, then free the POW's.
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.
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
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
Posting Permissions
Reply With Quote