[Swan] Need 250C help

[Jeramy Thibodeaux]

I can't argue with Glen's points!

I do however, personally think that it is imperative that you own a separate 
vfo for receive when operating this older gear.  It will help to keep you 
from chasing each other up and down the band.  I will also say that after 
proper warm-up, you shouldn't see large fluctuations outside what the 
manufacturer specs say.  If you do, then I would start looking for a 
problem.  Some very common ones are the band switches or relays requiring 
maintenance on these radios.  Often times a good cleaning will suffice.  It 
is also recommended to add a fan for cooling the finals.  The matching vfo 
(model 210) is hard to come by.  I recently picked one up after waiting 
patiently for six years.  These are either extremely rare? or people just do 
not part with them?  You can find other vfo models that can be made to work 
with this unit or build your own.  I was planning to build my own when I got 
lucky.

Jeramy Thibodeaux
kg4azt

----- Original Message ----- 
From: "Glen Zook" <gzook at yahoo.com>
To: "Greg Mijal" <bluebirdtele at earthlink.net>; "Discussion of equipment 
manufactured by Swan" <swan at mailman.qth.net>
Sent: Friday, June 01, 2007 10:50 PM
Subject: Re: [Swan] Need 250C help


> True, but how many amateur radio operators even know
> about the Transcom units?
>
> The Swan 250 series is "OK" for "hunt and pounce" type
> of operation.  But, for any operation that involves
> lengthy transmissions or series of transmissions they
> do "tend" to be a bit "drifty"!  Some units are better
> than others but they all seem to drift quite a bit.
>
> The fact that the VFO covers the entire 4 MHz of the
> band with the "band set" variable capacitor doesn't
> help with the stability at all!
>
> It is a fault with the vast majority of Swan units (HF
> as well as 6 meters) in that instead of using a
> relatively narrow VFO (i.e. 5.0 MHz to 5.5 MHz) and
> heterodyning the frequency to various bands with
> crystal controlled oscillators Swan chose to mix the
> VFO directly with the SSB generator.  The result is
> the higher the band the higher the VFO frequency has
> to be.  The higher the VFO frequency the harder it is
> to get good stability.  Also, the harder it is to get
> decent calibration.
>
> Glen, K9STH
>