[TenTec] Custom Filters?

[Warren Walsh]

At 08:50 PM 12/25/97 -0500, Warren Walsh wrote:
>
>The following message was taken from the CQ-CONTEST reflector archives.
>I hope it helps!
>Happy Holidays
>Warren Walsh - K2BM
>wwalsh@intac.com
>
>-- 
>----------------------------------------------------------------------
>-----
>| Ron Stone, GW3YDX -    EMail ron@gw3ydx.demon.co.uk                 
>                               
>----------------------------------------------------------------------
>-----
>Chaps
>
>
>Those amongst you who are owners of the Omni 5 and 6 transceivers will 
>know that the NAR filter on CW is built for a 750 Hz audio tone. 
>Tuning into a tone lower than this (I prefer around 300 - 400 Hz and 
>using the narrow filter attenuates signals unacceptably. 
>
>I have spoken to Ten Tec about this problem (some while ago) and they 
>said that they did not intend to offer any filter options above what 
>was available then. The position has not changed. 
>
>Ten Tec filters are made by Network Sciences in Arizona. I spoke to 
>them about having a special filter made. They were quoting $200 for a 
>single with quantity reductions. At the time I was not prepared to pay 
>$200, and sent PacketCluster messages to the various Cluster systems 
>to see if there was any interest for such a "low note" filter. 
>
>In all, about 6 people replied saying they would buy a filter at a 
>reasonable price, but there are now more Omni 6's around and interest 
>may be greater. I am prepared to go to Network Sciences again and talk 
>pricing if others are interested.
>
>The proposal is to commission the construction of a filter with the 
>following specifications (same as the current Model 217 - for 750 Hz 
>note, filter - but with 400 Hz bandwidth and optimised for 400 Hz 
>note)
>
>Centre freq - 9.000400
>- 6 dB Bandwidth - 400 Hz
>- 6:60 dB shape factor 2 : 1 or better.
>- Insertion loss - 7.5 dB
>- Ultimate rejection - 90 dB
>- Z in / out - 200 ohms
>- Poles - 8
>
>Please let me know if you are interested. Also please (via Cluster, DX 
>and Contest Clubs etc) tell your friends with Omni 5 and 6 
>transceivers. I'll wait a month or so and then issue a bulletin with 
>responses and pricing info. 
>
>Trey - if this is a bit off the mark for the Contest Reflector, 
>apologies, but I can't think of a better forum.
>
>73
>Ron
>
>ps - The Omni is not the worlds best SSB transceiver. Have you 
>measured the filter response ? Mine is 2.0 KHz at the -6 dB point !! 
>Network Sciences have built specials for 2.7 KHz so that operators can 
>sound human on SSB. 
>
>pps
>
>I have no connection at all with Network Sciences and am not gaining 
>any financial advantage from this !
>
>



I'm sorry I did not elaborate in my last message.  This message was taken
from the
SEPTEMBER 1995 CQ-CONTEST mail list archives.  I never did order any
filters, due
to not having the extra cash at that time.  I believe Ron put an order through
around December 1995 or January 1996.  So this information is at least two
years old.
I saw the custom filter message on this reflector, and remembered that
someone else had
been down this route before.  I decided to try and help out by looking back
through the
old archives, and found Ron's original message.  There are additional
messages in the 9/95, 1nd 11/95 CQ-CONTEST archives,  these can be found by
going to the following:
	http://www.contesting.com/_cq-contest
The messages are archived by monthly folders.

I would also suggest sending Ron Stone an email, and ask him for further
information.

Thanks
Warren Walsh - K2BM
wwalsh@intac.com


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