I think what is being said is that the carrier null is much more critical
with the Inrad 2.8 over the TT 2.4. The 2.8 does not affect the nulling
adjustment. It's just that the null adjustment is probably not good enough
any more. And, in fact, it does not seem to be possible to achieve the depth
of null (after the 9 MHz filter) with the IN 2.8 as it was with the TT 2.4.
Looking at the curves for example, for the Inrad 2.4 filter (I have no
curves to look at for TT 2.4 so just for the sake of comparison I am using
the Inrad curve), the filter attenuation at 9.0 MHz is about 35db. The
attenuation of the Inrad 2.8 filter is only about 17db at the carrier
frequency. So that means that the carrier null is already at a disadvantage
of 18db. Just to get even with what the 2.4 filter will do for you, you need
another 18db of null. It may not be possible to acheive another 18db with
careful nulling.
However, I think my carrier is down reasonably far, I get no bad reports.
Looking at the output with a scope and nulling, I seem to be able get it to
pretty much down to about 33db or better below a 100 watt ssb output. That
is about 50 mW of carrier. Not great but no complaints.
Chuck, KE9UW
> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com]On Behalf Of Steve N4LQ
> Sent: Friday, January 07, 2005 21:28 PM
> To: tentec@contesting.com
> Subject: Re: [TenTec] 2.8khz and Carrier Balance??? (LONG!!!)
>
>
> Well I understand the need to adjust the carrier null but what I do not
> understand is the recent claims that somehow the 2.8khz filter
> has something
> to do with getting the carrier null out of adjustment. Sure, it's a good
> idea to check it and tweak it up...er...down but I don't think
> changing the
> filter affects anything.
>
> Steve N4LQ
>
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