[Hammarlund] Thanks!

[Kenneth G. Gordon]

On 11 Dec 2011 at 10:55, Brian Burns wrote:

> Hello All,
> 
> Thanks very much for all your replies to my inquires about the HQ-145.
> I even learned how to spell Hammarlund!

Let me put it to you this way: if you DON'T buy that HQ-145 for 
$50.00, you will be kicking yourself...and if you don't kick 
yoursefl, one of us might do it for you.

> Of course answers always bring up more questions like:

...of course...
 
> ~ Silver mica disease?

In some silver-mica caps, especially, those in some IF cans, the 
silver will "migrate" across the mica and short out the cap, making 
it impossible to tune the transformer. The caps then have to be 
replaced, preferrably with dipped ones. Sometimes this problem can be 
difficult to track down if you aren't already aware of it, and 
sometimes it can be a bear to fix. 

> ~ 6C4 disease?

Hammarlunds used a single 6C4 as the HFO in many of their receivers. 
Unless you get a good 6C4, the receivers can be very unstable. This 
is why the Military specified special 6C4WAs, or similar.

MOST 6C4s are crap, especially those made for the commercial, vs 
military, market.

For instance, my HQ-110C, shortly after I put it in operation, began 
to be severely "yanked" off frequency when I was listening to a 
strong CW signal. I changed the HFO tube several times, using very 
cheap, off-brand but NEW 6C4s which I had a pile of, and got no real 
difference in operation.

After talking with Carl and a couple of others about my problem, I 
bought a couple of sleeves of NIB Sylvania 6C4WAs. After I 
substituted one of those in the HQ-110Cs HFO, I had no more troubles. 
The receiver is unusually stable now.

During the discussion, it was pointed out that Sylvania brand 6C4s 
seemed to be far more stable than others.

I also substituted a WA (military) version of the 6BE6s, and THAT 
made a difference too.

> So, is there anything published on boatanchor restoration in general,
> or Hammarlunds in particular?

Yes. Several places. See Andy Moorer's site (jammin' power), for one. 
Another is the site Todd mentioned, the Western Historical Radio 
Museum.

I think if you would simply Google the words Hammarlund restoration, 
you would find enough sites to keep you busy reading for at least a 
year.

Ken W7EKB