[TenTec] Corsair II warble

[Bob Towers]

Tom,

Thanks for your comments...

There's no crystal for the worst band, 14.000 MHz!

I'll have a look at the band switch contacts. The Corsair manual has a dire warning in it about cleaning the bandswitch contacts - something to do with the lube they used on assembly.

And yes, the AFC does handle the drift, but:

a) on some data modes on MixW the AFC button is greyed out, ie MFSK, which is the most difficult to tune

b) AFC doesn't stop warble on transmit!

73,
Bob
MM3KDZ

*********** REPLY SEPARATOR  ***********

On 30/03/2004 at 12:39 Tommy wrote:

>Bob....
>
>Alan has a good point. If you look at the schematic of the Corsair, you
>will
>find the xtal mixing scheme used for each band. There may be some
>possibility for you to replace the xtals for the 'bad' bands with more
>stable xtals...along with some temperature compensating capacitors in each
>band's circuit. It could possibly provide you with the stability your
>looking for in that rig. You also might think about really cleaning the
>contacts on the band switch really good as with age, those switch contacts
>do tend to get 'dirty'.
>
>But isn't it also true that AFC in most PSK programs will easily handle the
>present drift you are experiencing?
>
>Tom - W4BQF
>
>----- Original Message -----
>From: "Bob Towers" <mm3kdz at beeb.net>
>To: <tentec at contesting.com>
>Sent: Tuesday, March 30, 2004 8:22 AM
>Subject: Re: [TenTec] Corsair II warble
>
>
>
>
>*********** REPLY SEPARATOR  ***********
>
>On 30/03/2004 at 07:51 Tommy wrote:
>
>>Unfortunately Bob, you have a good radio that was designed many years
>>before
>>digital modes were used and at that time, the stability you are quoting
>>would be way above par for those radios. If your getting a max of 10Hz
>freq
>>drift, count your blessings. The PTO is not going to do any better.
>>
>>Tom - W4BQF
>>
>Tom,
>
>Many thanks for the reply...
>
>You are right, but what intrigues - and annoys me - is that on 15m and 30m
>the stability is more than good enough for me. If the PTO is this good on
>these bands, how come it deteriorates when running 20m, for instance? It's
>a
>mystery to me. Also, I have a Kenwood TS-120V which isn't a patch on the
>Corsair as far as performance is concerned but which has pretty good
>stability, better than the Corsair on 20m.
>
>73
>
>Bob
>MM3Kdz
>
>
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