[Vintage-Radio] HRO progress

[Vic Rosenthal]

Thanks to everyone who advised me on my HRO-5TA1 project!  Yesterday I removed 
the VR tube and wiring that had been added in place of the 6J5 first audio 
stage, rewired the 6J5 and the limiter stage (which had been changed to who 
knows what), installed the correct 10K pot for limiter threshold in place of the 
switch that the unknown butcher had installed, and replaced the arcing B+ toggle 
switch with a good one.

I also replaced a couple of remaing paper capacitors and a couple of resistors 
that were twice the correct value, as well as two bad tubes!  It now has plenty 
of gain and the limiter works as it should.  I added a heavier bleeder to the 
homebrew power supply that came with it to reduce frequency change when 
adjusting the RF gain control.  I am going to look into finding a way to 
regulate the HFO screen, possibly with a high-voltage zener.

I used the tie-wrap method to remove the dial as suggested here, and it worked 
like a charm!  I didn't need to go as far as to remove the knob and improvise a 
puller; just having the tie wraps to pull on made it easy.

I stripped the dial with paint remover, and just primed it with etching primer. 
  Later this evening I intend to paint it gloss black.  Interestingly, I found a 
color photo of an HRO dial that is for sale on e-bay 
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4671&item=5734818761&rd=1>
and it is definitely the color mine was -- not black.  I am assuming that the 
paint faded in the past 60 years....if anyone is old enough to remember what a 
new HRO-5TA1 dial looked like, please let me know.

Finally, I am looking for a good readable manual copy.  I know W7FG has them, 
but I once purchased a Hallicrafters manual from him and was unhappy with the 
quality (illegible, missing sections, etc.).

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco