• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Reply to thread

I have a very nice HQ-129 and have had most of the others along the way.  I usually start with the AC power cord and work my way down stream.  Replace the power cord with a grounded 3 wire cord.  Next, I check the power transformer voltages with the rectifier tube removed.  Then it's on to the electrolytics.  They should be replaced.  Once that is done you can replace the rectifier and continue your journey.  From here on it is up to you how detailed you get in your restoration.  I would think weak RF in the high bands might indicate soft RF and IF tubes or possibly a re-alignment is in order.  The HQ-129 manual has a voltage and resistance chart as well as re-alignment procedures.  This is a good place to start the post-power supply troubleshooting.  Most of the resistors will have drifted high and all the paper capacitors will need to be changed.  These are the basic steps in returning a boat anchor to operational condition.  Of course, there are always the "head scratchers" where a good magnifier and a curious set of eyes may be the solution.  The journey can be a real treat even with the obstacles.  The HQ-129 is a great receiver and should provide you many hours of enjoyment.


Disclaimer:  My statements are my own opinion and have worked for me with good results, but by no means do they guarantee a risk-free evolution.  Consult the manual as well as tips from others who have been there.


Enjoy,

Marc


P.S. My apologies for rambling on about restoration when your original question was about hum in the audio.  I had buzz in the audio of the 129 even after changing the electroytics and it turned out to be a bad audio amplifier tube.  You might try that.