On Wed, 11 Feb 2009, Paul P wrote:


wrote in message
...
On Feb 9, 9:14 pm, " wrote:
Looking to buy a 3395 AM filter as used in early tube Heathkit
receivers..any other suggestions on receiving AM with homebuilt filter
system? TNX 73 Harold Followup: I am looking for a 3395 KHZ.
AM Filter for a Heathkit SB301 .The AM filter was offered as an Option .
The SB 301 will not receive AM without the optional filter....It has AM
detector and everything but the filter..I thought someone might have worked
out a substitute for the Heath filter..like a high Q tuned IF can or
whatever... TNX Harold

I worked on a National NC-300 a few months ago. It had a conversion from a
coil to a crystal at the second converter stage.
About half way down the page: http://www.ppinyot.com/N/national/national.htm
look for the "Second Converter modification at V3 6BE6" paragraph. Schematics
and FNBs are on BAMA.

The crystal used in the NC-300 is not at your frequency. But a crystal
company should be able to make you one. I purchased Hammarlund specific
crystals from http://www.icmfg.com/ The crystals were about 25 bucks each.

AND the woman that answered the phone is not just a receptionist. She knew
exactly which crystals I needed for the Hammarlund and what overtone and
impedance!!! Not that she is a woman but she knew exactly what the vintage
crystal replacement I needed!

Who knows, but likely they have it on computer.

The old crystal manufacturers tended to keep such information around, and
certainly once they had the information because someone had sent it to
them to get a needed crystal ground, they'd surely have kept it. So
after a while, they could just look up the information. If they bothered
to computerize it, then all they'd have to do is type in some search
terms, and out would pop the needed information. That wouldn't require
someone who knew all the details by heart.

Michael VE2BVW