Heathkit HR-10B

[W1RKW]

Anyone know anything about the Heath HR-10B receiver by any chance?  I have one I'm trying to resurrect to listen too when hanging out in the garage (outside speaker). The receiver seems deaf.  I know the audio amp and detector are working but it doesn't seem to want to be playful. On the scope I can see the crystal calibration signal from input all the way up to the 2nd IF stage.  I seem to lose signal between the 2nd IF amp and the detector and yet all components seem OK.

[wb1ead]

Hi Bob..well about 25yrs or so ago i decided to outfit the station here with a complete Heath station..a DX60B/HG10B/HR10B..the 1st two worked out quite well but the HR10B unfortunetly was not the most effecient/sensitive rcvr ever owned..matter of fact it wouldn't hear much above 20mtrs as i recall..i had a 5 tube Hallicrafter the S120 or similar that ran circles around that one on the higher bands..even the Heath Mohican..a small SS rcvr put the HR10B to shame..sorry Bob but it's not gonna be a big performer..i even tried hooking a PA19 pre-amp to it but no soap..on the lower bands 80 thru 40 it was as i remember just OK..granted someone out there will give it high praise but honestly it ain't gonna happen..it needs a major re-vamp in the elec eng dept..IMHO
             Hope i didn't offend ya Bob..you did ask for any user experience...well anyway 73 de DAVE

[w3jn]

Worst.  Receiver.  Ever.

Best thing to do is swing it by the line cord against the wall, then set fire to the remains so you're never tempted to put it back together.

Seriously, could be an alignment problem with the detector coil.  If you can't get a relatively sharp peak, the internal capacitors are bad in the can.  The IF on this is 3.some megahertz so you won't get a peak like you will with a 455 KHZ IF can, but you should find a peak.  Slugs all the way in/all the way out = bad caps in the coil.

[WQ9E]

The HR-10B was one of the "population control" measures instituted by old timers to make sure most novices got discouraged and didn't stick around to crowd the bands    It is what I would call a consistent receiver because it is mediocre on all modes but it does work well enough to make some contacts and in proper condition should be good enough to monitor signals in your garage.

If your scope is still showing a good signal at pin 6 of V-4A and it is gone (or greatly diminished) at pin 2 of V5 then T3 has to be the prime suspect.  If the signal is also low at pin 6 of V-4A check for DC voltage to see if the T3 primary is open.  Check resistance from pin 2 of V5 to ground to see if the secondary of T3 is open.  If neither is open then, as JN stated, one of the caps inside the can is likely bad.

By the way, I also own the British version of the HR-10B which is known as the model RA-1 "Basic Amateur Receiver".  This is similar to the HR-10B and bears a close resemblance but it also covers 160 meters, has workable AGC on CW/SSB with switch selected upper and lower positions, has an adjustable noise limiter, uses a VR tube to regulate the HFO voltage, and has a nice Eddystone reduction drive that allows fine tuning using the main tuning knob.  I am not sure how much more they charged in the UK but if close in price it is too bad that Heath didn't sell that version over here.

Rodger WQ9E

[W1RKW]

Hey Guys,
I'm not offended by the criticism of having a notoriously deaf receiver.  I did have one that worked quite well on 75m.  That's all I was hoping to do was get it to work on 75m and maybe 40m.  The other bands I don't care about.

I did peak the various coils and all seemed to be peaked. 

I'll poke with it this weekend and look at T3.  I don't know if the cal signal that I'm looking at up that point is of sufficient level. There could be other problems in earlier stages.  I have no specs to judge the levels. The schematic only seems to show DC levels and that's it.

If it comes down to it, I'll take JN's advice and heave ho with a line cord swing ;-).

[WU2D]

This handsomely-styled amateur receiver is a perfect match for the DX-60 Transmitter, providing complete high-performance station receiver facilities at low cost!
The HR-10B is designed for amateur band coverage only on 80 through 10 meters, for maximum accuracy and stability. Each band is separately calibrated on a large, easy-to-read slide-rule dial.

The tuning dial is illuminated and provides over 6" of bandspread for precise frequency
settings. A carefully-designed diode detector, plus BFO, tunes AM or CW and SSB signals.
The 7-tube superheterodyne circuit features an RF stage for added sensitivity and employs a half-lattice crystal filter for excellent selectivity characteristics ... a necessity with today's crowded band conditions. Two IF amplifiers operating at 1680 kc provide good image rejection.

Other features include: "S" meter to aid in tuning and determining relative strength of
received signals; a 3-gang tuning capacitor to assure proper tracking of all circuits
rather than "Broad Banding"; a front panel dial calibration control and provision for
a plug-in 100 kc crystal calibrator (see HRA-10-1 below) to provide accurate dial
calibration at any 100 kc point across the band.

Other panel controls consist of: antenna trimmer, bandswitch, tuning, BFO tuning,
RF gain, AF gain w /AC on-off switch, xtal. calibration on off, STBY /RCV, BFO on/off,
AVC on off, and automatic noise limiter on /off. An accessory socket is provided on the
rear chassis apron for receiver muting, etc., and a speaker jack is provided for use
with any 8 ohm PM speaker.

21  lbs.

Kit HR-10 ... NO MONEY DOWN, $9 mo ....................... $82.95

My heavens was I jealous of my Novice buddy Billy who had one of these and a DX-40 while I had a lowly Command set and BC652 and was stuck on 80M with a long wire. Now I know that he was not hearing much on his his ground mounted Gotham Vertical.

Seriously - what did Heathkit do that they could not make a receiver with 7 valves?

Mike WU2D

[K1ZJH]

Wish I had a schematic to look at.. But, perhaps there is something wrong with the detector? DC return for the diode detector could be open, making the RX seem deaf.  It is kind of hard to troubleshot over the internet.

I was told the local oscillator ran at 1/2 the LO frequency on the upper bands, to improve stability. That purportedly was one of the reasons the receivers were so dead on 20, 15 and 10 meters.

If you do toss it by the cord, send me the two IF xtal filter crystals--doing a HBR receiver and could use them in the 1682kHz IF

Pete

Thanks to Rodger,  a schematic appeared in my email. Here's a long shot, check from pin 5 of V5 to ground, you should be reading about 437K-ohms resistance. If one of the three resistors is open (bad solder joint?) the recovered audio will be very puny.

[W1RKW]

Thanks Pete.  I'll take a look at V5

[W1RKW]

Pin 5 appears to be a heater connection.

I'm able to hear very very slightly some signals on the 75m band.  Can't make out the mode but there is something there.  The other thing, with the crystal calibrator running, I'm not getting a tone whatsoever.  BFO injection is present but nothing audio wise other than a slight hiss when turned on.

[K1ZJH]

I didn't keep a copy of the schematic, and may have had trouble reading the pins. One thing I did notice was that the radio has a separate AGC detector.  Does the S-Meter show normal activity?

[W1RKW]

No, S-meter doesn't move even with the cal crystal running.

[Tom WA3KLR]

Bob,

I'm curious to see a top inside view of the HR-10, if you can.

Thanks.

[K1ZJH]

The two HC6/u crystals in the IF half lattice filter  are there, right?

[WZ1M]

I have the xtals, email me direct.
Regards,
Gary..WZ1M

[W1RKW]

Sorry for the delay.  The USN keeps me very busy.

Crystals are in place and pass the signal out to V4 and V4 does seem to be doing its job.

Picture of chassis top side attached.
B

[K1ZJH]

I have the xtals, email me direct.
Regards,
Gary..WZ1M

Gary, since the xtals aren't missing in 'RKW's receiver, I am interested in them.

Email sent.

Pete

[KD6VXI]

Sorry for the delay.  The USN keeps me very busy.

No reason to be sorry, thanks for your service.

Grew up in Navy Diego...  err San Marines....  I mean, San Diego, so know how busy it gets for you guys.

--Shane

[Tom WA3KLR]

Thanks for the photo Bob.

Looks like a good size power transformer for the power draw.

[WQ9E]

Bob,

Pull V-5 and use your scope to see whether you are getting signal through the secondary of T-3 to Pin 2 of V-5.  Since you stated earlier that V-4 appears to be amplifying this will help you narrow it down to a T-3 problem or a problem in the detector stage.

[W1RKW]

OK, pulled V5.  I'm getting approximately a 1.68MHz sinewave at about 600mV at pin 2 of V5. VFO is set at 4.0Mhz with the crystal calibrator on.  I have no idea if 600mV is an adequate level  or if 1.68MHz is right. Something tells me no.  What is interesting however, I get the 600mV with a x1 probe.  If I go to x10 on the probe, the signal level drops to about 250mV.  I thought maybe I had a bad probe so I tried another and got the same thing.  I'm wondering if T3 is the problem and the x1 setting is changing the match t hus giving a larger outpoot.  Even with the x1 setting there is no change in audio (silent). Anyone know what the IF frequency is supposed to be?

Shane,
Appreciate the thought but I can't take credit for being a USN serviceman.   I'm not in the USN.  I work for the USN via a contractor.

[WQ9E]

Bob,

Is your BFO on?  If so that is probably the signal you are seeing at pin 2.  If the BFO is off then you do have the calibrator signal making it through although to confirm you should kill the calibrator to see if it disappears.  You could also vary the BFO and depending upon your scope capabilities you will be able to see the slight frequency shift on the scope display.

With your X1/X10 probe switching, are you accounting for the times 10 attenuation factor of the X10 probe?  With the X10 probe, the signal would be expected to be one tenth of the level of the X1 probe EXCEPT that the resistive and capacitive loading is less with the X10 probe so that when measuring at RF the X10 probe will provide a reading greater than the expected 10% of the X1 reading.  For most accurate waveform measurement you should also adjust the compensation of the X10 probe; this is generally done by connecting the X10 probe to the scope calibrator output and display a few cycles of the calibrator signal while adjusting the compensation (may be in the probe body or the connector depending upon the probe, see your probe manual) control for a proper square wave shape.  This isn't too critical for what you are doing now but it is a good habit to acquire.

The IF frequency of the HR-10B is ~1682 Khz.

Rodger WQ9E

[W1RKW]

Hi Rodger,
The scope display is doing the opposite of what I would expect i.e., that a x1 setting would load down the signal.  And yes, I was accounting for the x10 attenuation.

Yes, I can see the BFO switch in and out. No audio passes when the BFO is on but more hiss is noticeable.

Injecting an audio 1kHz squarewave signal from a hand held injector probe at the detector input (output of T3) passes OK to the detector audio amp.

It's puzzling.

[W1RKW]

It appears the problem is maybe toward the front end before the crapstal filter. T1 shows a little bit of corrosion on the clip that holds it to the chassis.  I didn't see this before but it maybe a clue.