> If we insert 6-pole or 8-pole filters instead of 4-pole filters,
> we will have more insertion loss - and it is not trivial.
> I was thinking about using my filters from my OMNI VI+ too, but I
> am afraid there might be too much insertion loss.
>
> Has anybody done any testing with this or already asked TEN-TEC?
T-T supplies the higher pole filters for the optional positions
I recently installed both the standard T-T 500Hz/#217 and 1800Hz/#218) roofing
filters. It would appear that the gain compensation for these filter positions
are set for the T-T 8-pole filters.
There was some discussion a while back about reduced IMD performance and
possibly some noise related to the extra gain stage associated with the 500Hz
filter. Can't comment on IMD, but a have observed no increased noise or other
artifacts associated with the use of the filter.
In other words they work fine.
Grant/NQ5T
> This Roofing Filter subject has me a bit uncertain.
>
>
> 73
> Rick
>
> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com]On Behalf Of Zivney, Terry
> L.
> Sent: Wednesday, January 14, 2004 10:04 PM
> To: tentec@contesting.com
> Subject: [TenTec] 9MHz 500HZ filter
>
>
> I note in my new Orion that the supplied roofing filters have 4
> crystals each, which is sufficient given their intended purpose.
> The accessory filters for the Orion, since they are also used in
> older Ten-Tec gear, have 6 or 8 crystals, which among other
> things
> surely increases the cost.
>
> International Radio (www.qth.com/inrad) sells a kit with 4 - 9Mhz
> crystals and the necessary capacitors to make a 600Hz filter
> with 200 ohms termination impedance, which I believe is the same
> impedance as the Ten-Tec filters. This kit, without a circuit
> board, is only $24. Although a purchaser of a $3,000+ radio
> may not wish to cut corners on a $109 filter, owners of older
> rigs may. In particular, given the cascading nature of the
> filters
> used in the OMNI VI, this may be a way to upgrade for relatively
> little cost.
>
> Anyway, it's an idea.
>
> Terry Zivney, N4TZ/9
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