TEN TEC OMNI FILTERS. SPECIAL LOW NOTE DESIGN
ron at gw3ydx.demon.co.uk
Fri Nov 24 18:14:38 EST 1995
| Ron Stone, GW3YDX - EMail ron at gw3ydx.demon.co.uk
Please see the messages below. It is now nearing time for "final
calls" for this one.
Sent in September
Subject - TEN TEC SPECIAL FILTERS
You will recollect that I sent out a bulletin enquiring if there
would be any interest in custom filters for the Ten Tec OMNI V
and OMNI VI transceivers. You were one of the people that replied.
There was a lot of interest and I have since
contacted the people who make filters for Ten Tec.
They are willing to produce filters but of course the more they
produce the cheaper they are to the end user. For every filter they
design there is also a non recurring engineering charge irrespective
of how many they make. This charge is normally 395 dollars US. We are
being given special treatment in this case and as hams this charge
will only be 195 dollars US.
The filters in question are a) A 400 Hz bandwidth CW filter
centered on 400 Hz audio note for those of us hunting DX and
who like a lower note than the Ten Tec 750 Hz note filter (NAR posn)
and a HiFi SSB filter with a 2700 -6dB bandwidth for TX and RX.
The non recurring engineering charge has to be applied to the
filters being made. I have had to guess how many filters may be wanted
and that leads to the following schedule.
UNIT PRICE 9.0 MHz filter for CW 6.3 MHz Filter for SSB
QTY 10-19 $ 144.50 $ 149.50
20-29 $ 129.50 $ 134.50
If we buy filters in the quantity Ten Tec buys (thousands) then we
get down somewhere near the Ten Tec prices. For instance if over
100 were bought they would get to below 100 dollars.
If you would like one of the above filters please contact me to advise
you are prepared to pay up to $144.50 per filter (CW) and $149.50 per
filter (SSB). YOU DO NOT HAVE TO REQUEST BOTH and they are priced
above separately. Sorry there is no saving to buying both filters !!!
Specifications of the filters follows
PARAMETER 6.3 MHZ SSB 9.0 mhZ CW
Center freq 6.29950 MHz 9.000400 MHz
Poles 8 8
6 dB BW 2700 Hz min 400 Hz min
60 dB BW 5500 Hz Max 1000 Hz max
Ripple 1 dB Max 1 dB Max
Ultimate attenuation 90 dB Min 90 dB Min
Insertion loss 2.5 Db Max 12 dB Max
Source and load 200 ohms +/- 10% 200 ohms + /- 10%
Package As TT filters As TT filters
( plug in on appropriate circuit card)
I can't offer you a definite price yet. That depends on take-up by
who expressed an interest but have yet to reach into their pockets.
If more than 20 people go ahead then you all get the filters at the
lower price. I doubt if there will be that level of demand though and
my guess is that I'll end up with a dozen or so serious people for the
CW filter. Only two people asked about SSB. Out of interest the cost
for two filters is $275 each, because of the swingeing effect of the
$ 195 non recurring engineering charge. One filter (if you are really
keen) will cost a cool $373 ! I for one would be unhappy to pay more
than $150 for a filter. So I did not list the smaller quantities
resulting in a greater price.
I am not doing this commercially so cannot afford to lose on it. If
wish to go ahead (once the numbers of serious people are established)
it will be a case of cash up front to me. As there is no profit margin
in this I cannot afford to have people change their minds or drop out.
DO NOT SEND ANY CASH NOW !!!!!! Two reasons
1) I am not yet sure that demand is sufficient even for the 10 filter
2) If most of the orders originate from the US it will be best for me
to ask funds to be addressed to a "banker" in the US. I'll deal with
the EU payments.
If any of you know other people with OMNI's who may be interested in
participating in this opportunity to acquire custom filters please
point them in my direction
To contact me (aside from Email)
Phone +44 1691 831111
Fax +44 1691 831386
PS If anyone thinks this is a commercial advert and should not be on
the reflector, I AM DOING THIS FOR NOTHING, in fact these things
(I've done them before) usually leave me out of pocket.
PPS If you want an official Network Analyser plot of the passband
and stopband of the filters ADD $13 (10--19 filters) or $ 11.30
(20 - 29 filters). This assumes everyone wants a plot. Single plots
will be dearer. Personally a pretty plot is something I can live
PPPS I intend to close the enquiries file on 25 December. I clearly
cant leave it open for ever.
SENT Today 24 November
We now have ten people interested in the special CW filters (400 Hz
bandwidth for 400 Hz center tone . Only one
in the SSB one, so I guess it goes no further.
Will you please confirm your continuing interest at the price of
$ US 144.50, plus shipping. For you guys in the US - please suggest
the cheapest secure way of delivery. We do not have US UPS rates over
here of course.
Once you have confirmed your interest and I have an idea of shipping
(cant be more than 10 dollars surely) I'll ask you to forward the
to an attorney friend of mine in Washington DC, who will act as a
collection point for the funds. If the filter manufacturer will ship
the filters direct to end users thats what I will have him do -
otherwise they get transshipped via DC.
Delay on building the filters is about 6 weeks. Only when I have all
the funds in will I go ahead with the bulk order. If anyone decides
to go ahead at this time I will have to cry on the filter makers
shoulder and request less than 10 at the 10 price. He may not accept
this and selling it will be really hard if more than one of you drop
out of the arrangement.
If you know of anyone else who is considering coming in on this - do
please advise them that single special filters will be going on for
Please confirm by Email and watch this space !
This is nearly the last call........
>From Dr. Eugene Zimmerman" <ezimmerm at DGS.dgsys.com Fri Nov 24 19:55:01 1995
From: Dr. Eugene Zimmerman" <ezimmerm at DGS.dgsys.com (Dr. Eugene Zimmerman)
Date: Fri, 24 Nov 1995 14:55:01 -0500 (EST)
Subject: SS rules in QST ???
Message-ID: <Pine.SOL.3.91.951124142303.19890A-100000 at DGS>
I mistakenly thought that an abbreviated set of rules in QST would work.
Your dilemma shows me that I was wrong.
I have gone back to read the SS announcement in the October 95 QST. You
are absolutely correct when you say it says
> that , " this leaves 6 hours of off time to be scheduled for your
> own prefrence. you can take all six hours at once or take an hour ( or
> part of an hour at a time."
It says nothing about a minimum of 1/2 hr time off at a time - only "or
part of an hour at a time". Part does -not- mean 1/2 hr minimum - it
means anything from a fraction of a second to 6 hrs. If the contest
announcements are going to be dumbed down and feel good, they -must- also
not contradict the actual rules. Or there must be a disclaimer that
warns the participants that they -must- get a copy of the "real" rules,
follow them and that the rules in the announcement may bear no resemblance
to the real rules. As written, the announcement allows full use of the
rubber clock -- I'll bet the envelop pushers could have operated the full
30 hrs without going over the 24 hr limit.
Now I do not blame Billy Lunt for the contradiction. This is no easier
than trying to explain a complex but important scientific discovery to a
public whose scientific awareness is at a third grade level. Those who
have tried to express complicated concepts in "lay" language that is
directed at the lowest common denominator know what I mean.
In the future, all of us will have to plan further in advance. You had
better send to info at arrl.org a few weeks before the contest in case what
happened to one of the other reflector posters happens to you - the robot
fails to respond. Or send a letter a few months in advance to Special
Requests and hope that the US mails are working. Or spend your dime on a
session with the ARRL BBS.
Seriously, Jeff, a significant error has been made in the announcement.
You are -not- responsible for a contradiction between the announced rules
and the "real" rules. Your host is an ARRL vice-Director. I think that
he can see to it that no one, least of all you or he, should suffer from
that inadvertant error. And I do not agree with those who say that you
should have gone out of your way to read the "real" rules -- maybe the
mail would have been lost, the robot might have been on strike, or you
would rather spend your money on some contesting accoutrement for your
station than on long distance charges to the ARRL BBS.
73 Gene W3ZZ
>From David Brian Ritchie <dbr at alumni.caltech.edu> Fri Nov 24 20:03:01 1995
From: David Brian Ritchie <dbr at alumni.caltech.edu> (David Brian Ritchie)
Date: Fri, 24 Nov 1995 12:03:01 -0800 (PST)
Subject: INFO response: HELP
Message-ID: <Pine.SUN.3.91.951124115801.2521C-100000 at alumni.caltech.edu>
The basic problem, to summarize, was this:
QST printed INCORRECT statement of the OFF-TIME rules. I fortuitously
(all right, I was too lazy and didn't operate as much as I should have)
complied with the REAL rules which you could only get off the Internet,
but in reading the QST SWEEPSTAKES announcement, you will all agree that
it says that there is no minimum time off requirement -- words to the
effect that you can take whatever 6 hours off that you want. The REAL
rules, obtained after the contest with difficulty from the ARRL state 30
minute minimum time off periods.
My point is this, if you can spend 1.25 pages announcing the contest,
somewhere in there you can state the real rules. Simply referring people
to an internet server that in actuality does not work (and for many QST
readers is unavailable) isn't good enough. Many people make the decision
to participate in a contest on the spur of the moment and requiring them
to try to get something off of the internet is too much of a burden for
MOST people -- maybe we can have a special rule for REAL contesters. Hi.
'73 Dave N6DLU
Dave Ritchie 818-683-8800 (w)
dbr at alumni.caltech.edu 818-683-8900 (FAX)
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