Redundant 2.7Khz 5 pole filters - what a waste.

[vk4cmv]

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

[Arie Kleingeld PA3A-2]

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


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Stewart Baker]

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
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list:

http://www.qsl.net/donate.html


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html