[Elecraft] Redundant 2.7Khz 5 pole filters - what a waste.

[Stewart]

I left the offset of my main RX 2.7k filter alone, as I figured 
that would be best for TX. Then adjusted the SUB RX filter offset 
to match the main, as no TX takes place thru that filter.

Can't say I notice any difference with the SUB RX performance, but 
diversity now works great.

73
Stewart G3RXQ


Thu, 25 Feb 2010 09:14:33 +0100, Arie Kleingeld PA3A wrote:
> Julian,
>
> About the filters being matched:
> Officially they are not but set the offset for both filters on 
.77 and you
> will have a fine pair for this BW.
>
> Because:
> - IF you listen at BW 2.7 in diversity, the filters might sound 
a BIT
> different but that's never a problem because reception on the 
two antennas
> is already different.
> - and second, they do not have the same passband (within a dB) 
anyway
>
> I have about this set of filters myself (I think about .15 
apart) and they
> work great, split as well as diversity. At the clubstation PI4D 
the K3 is
> favourite transceiver, especially on the bands where we have 
more than one
> antenna available in contests (160, 80, 40).
>
> The rest of my filters in main and sub (2.1 and 400) are 8 
poles, and so
> 'matched'.
>
> (FWIW:
> For the main RX I also have a 5-pole 200.
> During the CQ160 CW I sometimes cranked down to 200Hz, with two 
very
> different antennas connected (vertical and beverage). The phase 
difference
> between the 400 (8-pole) and 200 (5-pole) was there but not 
annoying because
> the receive pattern itself already shifted with matched 400's. 
The switching
> to the unmatched situation did not change much in the 
reception.)
>
>
> 73
> Arie PA3A
>
>
> -----Oorspronkelijk bericht-----
>
>
> Is there a market in 2.7Khz 5 pole filters (that were pulled out 
and
> replaced
> by 2.8Khz ones after the kit was bought and built) ?
>
> Could the two filters I have be considered a matched pair -.68 
and -.85 ?
>
> I wish I'd left them in the radio and bought a couple of 1.8Khz 
Inrad ones
> instead of the 2x2.8s - but hindsight is 20/20 as they say.
>
> 73 Julian Vk4CMV
>
>
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