[Hammarlund] HQ-180 mods

[Charles Ochs]

The "most bang for the buck" mod to this radio is to replace the 5U4 rectifier with a 5V4.

The 5V4 has enough current pass ability for this radio, and will provide a delayed application of B+, something always desirable in these old sets.

Not worth the trouble to try and make this into a 180-A. They really don't drift all that much with a good local oscillator tube--certainly no more than other tube sets.

I have a 180 that I have had for over 20 years, and use as my "bedside" radio. Still has the 5V4 that I installed when I first got the thing.

Most of the capacitors in this radio are of the ceramic type and, as a rule, do not fail. If the electrolytic is good, they don't need to be recapped.

Make sure you clean the contacts on the band selector switch, as well as all of the pins on those miniature tubes. My set was as dead as the proverbial door-nail when I first turned it on. Attention paid to all those mechanical connections made a world of difference.

The worst feature of these sets is the type of RF / IF transformers that they used. Not unique to Hammarlund, nearly all of the manufacturers of the period used these because they were smaller and cheaper than the designs used in earlier radios. Today, these are failing at an increasing rate. No replacements are available,  and repairing them is a PITA best left to an expert.

Full alignment will be required after these details are attended to.


Chuck

N1LNH