[Boatanchors] NEED HELP ON IF FILTERS

Fri, 21 Jun 2002 19:49:31 -0400

Gosh Dee, these old sets represent history. Why not make it work with all
existing and "proper" parts, and experience what it was all about "as
original?"

As such, you'll also be preserving something of value for the future too! If
you modify the HRO, in my opinion, you'll be doing an injustice to what was
very good engineering for its day.

Vy 73, AI2Q, Alex in Maine  .-.-.

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Dee Almquist
Sent: Friday, June 21, 2002 10:18 AM
To: [email protected]; [email protected];
[email protected]
Subject: [Boatanchors] NEED HELP ON IF FILTERS

Fellow BA'rs
Started an interesting project. National HRO-50T. Real clean radio & has
been recapped with new stuff. Got it working pretty well. Still have
problems with 3 of the coils sets to do yet but radio senseitivity not bad.
This is a very stable radio, almost no drift! However, it needs help in the
IF. Since it is single conversion, adjacent channel rejection leaves
something to be desired. Seems the easest way is a 455kc 8 pole filter @ 6kc
(and maybe another @ 4kc) for AM mode. Problem is the cost!!! Looking @
ceramic filters like we used in modern FM transceivers. But they dont have
the dynamic range that crystal filters have. Double conversion is a
possibility with miniture circuitry @ 60 kc. (limited space). Any one have
any experience with sooping up IFs? Any place on the internet for this kind
of project?
73 es Dee
W4PNT
http://w4pnt.8k.com
Patty & Dee's Marina Collectors of "firebottle" radios
Dee Almquist
534 W. Main St.
Waynesboro, Va. 22980
(540)249-3161 Cell: (540)480-7179

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