Hammarlund HQ-140-X

Discussion in 'Amplitude Modulation' started by KA4KOE, Jul 17, 2019.

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  1. KA4KOE

    KA4KOE Ham Member QRZ Page

    Well, I done did it again. I picked up a pretty clean 140 dirt cheap and got i working after the usually recapping. Since I am a receiver newebie and used to devices that work on the reverse concept, I am having issues....(with the receiver).

    On the higher bands above AM BC, the receiver will motorboat on signals. This may be due to a weak AGC tube.

    Also, when I switch to BFO mode, the VR tube goes out and there is an arc on the bandswitch. Something is drawing a lot of current. Need to check the rotary switch on the front panel and see if the problem is there.

    Cosmetics are really really good on this one. Sounds really good on AM BC. Very very clean on the bottom. 66580971_10218514553553684_5799276954314080256_o.jpg

    I messed up the meter by an accidentally mechanical shock, but I think it can be repaired....maybe. This is the version of the receiver with the round meter.

    Philip KA4KOE
     
  2. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    You’ve done an outstanding job on the 140x.
     
  3. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Motor-boating is often the failure of the cathode bypass in the audio output stage. In the HQ-140X that capacitor is C-48 a 10 mfd from Pin-8 to ground of the 6V6. This capacitor is a problem in receivers manufactured by other companies including Collins.

    Check R-45, a 0,05 mfd capacitor in the BFO circuit. Also, check C-41 a 5 pf silver-mica capacitor off Pin-6 of V-8 the 12AU7 that is the BFO tube and 1st audio. Silver-mica capacitors are raplidly acquiring sliver-mica disease which shorts out the capacitor.

    Glen, K9STH
     
  4. KA4KOE

    KA4KOE Ham Member QRZ Page

    Thank you, Glenn. I spent most of my time this weekend tapping stuff inside. I repaired the meter.
     
  5. KA4KOE

    KA4KOE Ham Member QRZ Page

    The receiver has 16 silver micas. All are over 60 years old. I should probably shotgun it and replace every single one. Most are under the IF cans.
     
  6. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    Those silver mica capacitors in the i.f. cans are going to be a pain in the posterior to replace. However, especially the capacitors that are on the side going to the plate of tube, are starting to have problems.

    You will definitely have to realign the i.f. stages after changing the capacitors.

    Glen, K9STH
     
  7. KA4KOE

    KA4KOE Ham Member QRZ Page

    Yep, figured I would need to realign the whole shootin' match.
     
  8. N6YW

    N6YW Ham Member Volunteer Moderator QRZ Page

    Fleep
    Oftentimes, Hammarlund’s have capacitors located inside the transformer cans, like the HQ-170 etc.
    they can be a real hassle to replace requiring the
    removal of the whole can. Not sure about the
    140 X but it’s worth mentioning.
     
  9. KA4KOE

    KA4KOE Ham Member QRZ Page

    Yep, it does have caps under the cans. I just made an order at Justradios.com. The caps were 1/2 what I would pay at Mouser. Even if the SM caps are "okay" and not related to the issues I'm having, they need to go anyway. Those caps are all over 60 years old.
     
  10. W7TFO

    W7TFO Premium Subscriber QRZ Page

    All that series, the HQ-120, 129, and 140 are excellent performers.

    Simple & robust, my favorite 'ham' models rather than the cast-panel iterations.

    They aren't the Super-Pros, but then again, nothing much else was. :-}

    73DG
     

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