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#1
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Boatanchors,
So I bought a HQ129X at a hamfest last spring as a project. Seller had started a recap job & decided to quit and sell it - price was right for me. When I got the radio home I plugged it in - DOA. I found a bad power cord, spliced in a temp and fired it up - the loudest HUM I've ever heard - holy crap. Anyways - I know how to use a soldering Iron but I'm in no way an electronics person - decided to see what I could do - I bought a recap kit for the receiver online and dived in this past weekend. Replaced the electrolytic can, then all of the paper caps except one - more on this one paper cap later. I then replaced the power cord with a new 3-prong cord and fired the beast up. No Hum (good). In fact the receiver works very well on MW and SW bands, quite sensitve and fairly selective - I was pleasantly suprized. Anyways - back to that one paper cap - Any identification on rating is gone from the cap itself - so I donlt know what to replace it with? I supose I could just leave it but I noticed it gets very hot with radio operation - the ones I replaced do not - so I suppose it's bad and should be rerplaced? If I remove the cap the radio is dead - Perhaps somone familiar with these radios can help me identify the rating of this cap? It's of different physical size to the others I replaced. The cap is direct connected between one of the pins on the VR105-OC3 tube and the Relay connector on the back of the Chassis. I'm not a wiz with reading schematics - Even though I identifed the tube and relay in the schematic I was unable to discern the right cap in the diagram.... Can anyone figure out the ratings of this cap from my description of it's location and let me know? Regards, Gregory. |
#2
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In article ,
Gregory Mosher wrote: Anyways - back to that one paper cap - Any identification on rating is gone from the cap itself - so I donlt know what to replace it with? I supose I could just leave it but I noticed it gets very hot with radio operation - the ones I replaced do not - so I suppose it's bad It MAY not be a capacitor at all, From your description, I would suspect a wirewound power resistor which would get somewhat hot in normal operation. You will have to locate it on a schematic to be sure. -- Rich Greenberg Sarasota, FL, USA richgr atsign panix.com + 1 941 378 2097 Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67 Canines: Val,Red,Shasta,Zero,Casey & Cinnar (At the bridge) Owner:Chinook-L Canines: Red & Max (Siberians) Retired at the beach Asst Owner:Sibernet-L |
#3
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![]() "Gregory Mosher" wrote in message ... Boatanchors, So I bought a HQ129X at a hamfest last spring as a project. Seller had started a recap job & decided to quit and sell it - price was right for me. When I got the radio home I plugged it in - DOA. I found a bad power cord, spliced in a temp and fired it up - the loudest HUM I've ever heard - holy crap. Anyways - I know how to use a soldering Iron but I'm in no way an electronics person - decided to see what I could do - I bought a recap kit for the receiver online and dived in this past weekend. Replaced the electrolytic can, then all of the paper caps except one - more on this one paper cap later. I then replaced the power cord with a new 3-prong cord and fired the beast up. No Hum (good). In fact the receiver works very well on MW and SW bands, quite sensitve and fairly selective - I was pleasantly suprized. Anyways - back to that one paper cap - Any identification on rating is gone from the cap itself - so I donlt know what to replace it with? I supose I could just leave it but I noticed it gets very hot with radio operation - the ones I replaced do not - so I suppose it's bad and should be rerplaced? If I remove the cap the radio is dead - Perhaps somone familiar with these radios can help me identify the rating of this cap? It's of different physical size to the others I replaced. The cap is direct connected between one of the pins on the VR105-OC3 tube and the Relay connector on the back of the Chassis. I'm not a wiz with reading schematics - Even though I identifed the tube and relay in the schematic I was unable to discern the right cap in the diagram.... Can anyone figure out the ratings of this cap from my description of it's location and let me know? Regards, Gregory. This thing is R-54, a power resistor, its supposed to run hot. The HQ-129-X is an excellent receiver despite being an economy model. There is a decent handbook on BAMA. It was the post-WW-2 version of the HQ-120-X, which was the first receiver with the Hammarlund patented crystal filter. The model number comes from the originally intended price: $129, it didn't sell for that for very long and eventually the price about doubled. The IF uses a combination of overcoupled transformers and critically coupled links to give a relatively flat bandpass and better skirt selectivity than is usual for receivers of this sort. Its main shortcoming is relatively poor RF selectivity (image rejection) from having only one RF stage, however the image rejection is still better than most receivers with a single RF due to the good design and high quality coils used. -- Richard Knoppow Los Angeles WB6KBL |
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