[Hammarlund] HQ-170 Mods

[Glen Zook]

Remove the serial tag and put it on a Collins "A" line receiver.  :>)

Seriously, check to see if the tunable oscillator tube has the heater ("filament") running all the time (even when the receiver is turned off).  If not, then add a small filament transformer that is connected before the off/on switch and run the oscillator heater from it.  Another thing that might help is to do what Hallicrafters did on many of their receivers and that is to put a high wattage resistor near the tunable oscillator that is wired across the AC line.  This is to keep the circuitry "warm" and therefore reduce drift due to "warm up".

Hallicrafters used "damp chasers" (a special resistor that was housed in a metal case).  However, a high wattage wire wound resistor will work.

Glen, K9STH

Website:  http://k9sth.com


--- On Thu, 10/8/09, bill bryant <wa5jul at yahoo.com> wrote:

Does any one know of any mods that will stop the HQ-170 from drifting?