One of those "looks really nice and works great" things - completely dead after purchase - we all know the story I acquired this to pair with a DX-60b / HG-10b combo to replace my venerable HW-16 that has earned its place on the shelf after completing W.A.S. and about 33 DX. Only have so much room - so the HR-10b/DX-60b + the ever-so-rare Heathkit HC-10 console will hopefully occupy that space. While awaiting parts for the very unexpected Drake 2NT "uh oh - she died!" project (see other thread!) I figured "no time better than the present" to test out the HR-10b and start a PS recap project. Let's just say I'm really glad I ordered the 20/20/20 cap kit from Hayseed a while ago... ugh. TOTALLY dead other than a dull 60hz hum - not very loud - "Works great" not in evidence. Here she is at the "let's put her on the Variac and see what she can do" setup (yes, I know "wrong knobs" - I have plenty of correct knobs that will go on after the repairs) : After a few hours of slow "Variac Time"... nice glow anyway After initial testing with utter deadsville - just a low hum, I knew it was HW-16 stuff all over again. So I put her on the bench - the actual construction is pretty nice! Good soldering, nice layout, good mechanical stuff - yay!! Glad to find all that. But someone had done an antenna jack mod (RCA to SO-239) and I don't think that long ago - the SO-239 is pretty modern looking, not a vintage silver-plated jack - good quality but not vintage stuff for sure. Just HORRIBLY done - solder joints so cold they pretty much broke off as soon as I touched them. More pix and stuff in a sec... sometimes this software times out and I lose all I've done Dave W7UUU
Here's the yucky SO-239 mess that fell apart the second I touched it - note the SO-239 sort of "cross-threaded" into the jagged hole... note that that red hookup wire is like 6 inches long and is the shield connection for the coax to the SO-239 that was added, with a cold solder joint to anything it touched as well as the coax center wire to the SO-239 - fell apart when touched - yet note the quality installation of the 1k resistor and the bypass capacitor - surely not the same person involved in both tasks:
So before tackling the bigger issue of the PS cap I figured I'd sort this mess out first - I installed a terminal strip on the calibrator socket screw, replaced a broken .005 uF bypass cap (darker one here is the new one), properly drilled out the SO-239 hole in the chassis, replacing the janky "whatever I could find" hardware with 4/40 stuff, and retrimmed the coax for the RF feed. Looks a lot better and now at least the SO-239 is properly done, IMO. Dave W7UUU
So for tomorrow, the filter cap project - easy-peasy - just quite a number of connections to make note of but will do in the fresh light of a new day Dave W7UUU
Dave, Know this receiver ... I built it in 1972 (high school electronics). Learned Vacuum tube & Point-to-Point wiring, and good soldering. Good for 80 and 40 meters, so-so on 20 meters, largely deaf on 15/10 meters. The 8-pin octal socket is for the HRA-10-1 plug-in crystal calibrator, these appear often at eBay, reasonable price. QRZ Q&A Technical Forum (2008) http://forums.qrz.com/index.php?threads/need-help-with-heath-hr-10b-mods.186054/ ==== The SO-239 was a "bad hack" .... IF RCA not desired (they work fine, cheap, widely available), the BNC is the preferred NO Hack change. ==== K6JCA article http://k6jca.blogspot.com/2010/11/improving-heathkit-hr-10b-receiver.html Electric Radio Magazine Articles: "Resurrection of a Heath HR-10B Receiver," Paschall, Issue 210, Nov. '06 "The Heathkit HR-10 Receiver," Hanlon, Issue 232, Sept. '08 "Heathkit HR-10 Receiver Update," Stock, Issue 234, Nov. '08 "Modifying Heathkit Crystal Filters," Stock, Issue 231, Aug. '08 ==== Many mods add a voltage regulator http://www.nostalgickitscentral.com/heath/73-index/articles/Update Your Heath HR-10-11-72.pdf
Thanks GB! I do in fact have the calibrator - safe and sound along with all the HR-10b tubes in a separate bin on the bench. Yeah - I figure it's only going to be an 80/40 deal - but I'm encouraged to hear it's at least "so-so" on 20m - to have any chance at a W.A.S. with it (always my goal with any new rig) I'll need 20m so I can use the beam. I will also look into the mods - thanks for the links. I always really appreciate the effort you take to research topics of threads and post links and stuff like you do - your efforts make this place a better community. Dave W7UUU
After hamming over 50 years and "working them ALL" I looked for a new challenge. 5-6 years ago I put a Drake 2NT and 2B on the desk and started working 40M CW exclusively into a dipole up about 60 feet. So far I worked 293 countries on 40M CW with this 50 watt crystal controlled transmitter and a 60 year old tube type receiver. Wanting another challenge I recently bought a HR-10B and a DX-60B. Like yours, mine needed some work. While the HR-10B definitely is no Drake 2B in performance, mine works quite well on 40M CW. I can "hear" a 0.1uV signal on 40 and the HR-10B is quite stable after a warm up. Selectivity is poor at best. So another challenge has started. So far using only the HR-10B and the DX-60B I have worked 47 countries this winter. I have a long way to go to match what the Drakes did. Due to the limitations of the HR-10B I may (or may not) stop if I work 100 countries. It does not take a modern $10,000 rig, 1500 watt amp, and a yagi at 100 feet to work lots of DX. Dick AD4U
Yes, that's true. The HR-10B is a single conversion receiver (1681 Hz, IF) that uses 2 crystals for a half-lattice filter between IF sections. That IF was popular in WW2 (BC-455 used 1415?) and some 1950s receivers. -- Hallcrafters SX-140 (inside view) I always suspected that the HR-10B was heavily influenced by the Hallicrafters SX-140 (1960-1965), across Lake Michigan (Chicago), which used the same IF. http://antiqueradios.com/forums/viewtopic.php?f=5&t=219290 I think EF Johnson Messengers (CB service in early 1960s) also used that IF. ==== Bill Orr had a great Product Detector (1959 Radio handbook and later) that used the 6SJ7 Octal tube. http://www.soemtron.org/downloads/disposals/6sj7.pdf In late 1970s, I drew out a schematic to replace the 3-diode (9-pin) vacuum tube with a suitable 9-pin version of 6SJ7 using that Orr idea (using solid-state diodes for AVC and ANL function. Dallas Langford spent considerable time on product detectors. http://www.ve7ca.net/BOT/51J/BfoPro.pdf
The 6SN7 (12AU7) was another option, which appeared in early 1960s issues of QST. http://amfone.net/Amforum/index.php?action=printpage;topic=26204. Pullen mixer (73 magazine, October 1961) http://www.w7ekb.com/glowbugs/rx/Pullen/A Like-New Mixer Circuit.pdf Product Detector by Robert Roehrig, K9EUI http://www.qsl.net/jms/Articles/hropd.html
Dave, My sympathies on the hack job of the SO-239 connector. I've got four HW-xx single banders, and one that has a decent board and OK chassis has this rear panel. This might be a JBWeld fill-and-sand repair with a plate with the correct lettering on it. Ted, KX4OM
