[CQ-Contest] again ICE vs. Dunestar, need your comments

Oliver Huber oe5oho at hotmail.com
Thu Apr 27 11:25:19 EDT 2000

hi contester.

1) a few of you might point out "it´s been discussed 100times"...

2) YES!! i already browsed trough the archives at contesting.com.

doing so - i found out that after some technical changes to both of
the filter-types ICE and Dunestar seem to have satisfied _and_ at
the same time unsatisfied users.

i also have to mention that a lot of the archive-files are way old,
back into 1994 and even beyond that. Dunestar now has the Model-600,
ICE sells their Model 419A, and both companies did eliminate the
cores after problems occured.

i feel like it´s time that you contesters out there, who played a
lot of years probably with a lot of different bandpassfilters in
your MS/SO2R/MM-stations hand out your very personal insights on
the topic BANDPASSFILTERS to help the young contesters!

please feel free either to send me your personal opinions directly
(with your acceptance i might do a summary and post it) or let´s
discuss it again.

i have to admit i _never_ saw any of the 2 filters infront of me,
i never touched them, i never opened them - so my knowledge is rather
poor. and _that´s_ why i need your comments, as i want to install
bandpassfilters in the MS-environment of OE5T (Dunestar 600 _or_
ICE 419A).

* technical information:
i only have that from the Dunestar 600, or better K6XX, who messured
them and gratefully provided it on the web.
ANYONE out there who can send me such info on the ICE 419A? ? ? !
does the 419A use the identical filters as the monoband-versions of
ICE are constructed, or are they using different ones in the 419A?
which of the 2 filter provides better out-of-band attenuation? i
read 2 different infos on that topic, one said, and i guess that´s
the right info, that Dunestar use high Q (series LC)-networks while
ICE uses a parallel LC-network. it´s clear to me that within a 50ohm
environment both filters will work as they should, when you have
other impedances in a realisitc environment things look differnt;
someone mentioned ICE would get along with worse SWR than Dunestar
(which in a way sounds logical, as Dunestar uses high Q and therefore
the voltages in worstcase are the problem).
i don´t have _ANY_ technical info on the ICE - any help out there?

* support question:
i read in an old(!) mailing to this list, that it is hard to get
the ICE-filters under a few month of deliverytime?! is that true?!?
how about Dunestar?
Dunestar once sent me a small brochure with literally small info.
i sent emails to ICE (www.inducomm.net, and the email they mention
there) but until now _no_ reply. maybe i should use another email?!?

* where should i finally buy these filters:
who´s the best source for Dunestar-products / ICE-products? i would
need address, email, phonenumbers...
i don´t know it - but is there a company in EUROPE that sells these

anyone has experiences with the WARC-models of either Dunestar/ICE?

* TOPTEN-Device
well, for the Dunestar model-600 i need something to switch the
filters, the automatic banddecoder-switch seems to be common in use.
for the ICE 419A i don´t - also i can(?) probably use the TT-decoder
together with the ICE.
how good is the ICE 419A switch if you use it often? would you
recommend to use an auto-banddecoder-unit? (we are manually tuning
the PA, and until now also manually selecting the antenna, so it
doesn´t really matter if we use one more switch, as you are really
involved with "thinking" doing bandchanges, hi ;-)


a lot of questions - but believe me, it´s not so easy to get all
the info you like to have, if noone is using these filters in
your region (i am not even sure how many OE´s are using such filters),
therefore this is my only chance to collect information - FROM YOU!

the contester who gives me the best feedback to my questions will
receive a small present from lovely Austria.

vy 73 es gl in contest,
                         de Oliver OE5OHO.
                         (one of the BCC)

PS: PLEASE contact me - if you can help me to receive ICE-technical
infos! TNX.

Visit:  http://www.qsl.net/oe5oho
Email:  oe5oho at hotmail.com
        oe5oho at qsl.net
Packet: oe5oho at oe5xbr.aut.eu

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>From Leigh S. Jones" <kr6x at adsl-63-194-227-234.dsl.lsan03.pacbell.net  Thu Apr 27 15:42:15 2000
From: Leigh S. Jones" <kr6x at adsl-63-194-227-234.dsl.lsan03.pacbell.net (Leigh S. Jones)
Date: Thu, 27 Apr 2000 07:42:15 -0700
Subject: [CQ-Contest] again ICE vs. Dunestar
References: <20000427102519.80806.qmail at hotmail.com>
Message-ID: <002b01bfb056$c801cb20$ede3c23f at kr6x.org>

With all due respects, I don't believe that Oliver's question regarding
filters is on target.

Now, clearly after the CN8WW results in last fall's CQWW contest it would
seem to be severely self indulgent for anyone who is not a Bavarian Contest
Club member to be caught preaching to any BCC member about station design.
Undoubtedly, any CN8WW veteran should be qualified to teach graduate level
courses on contest technique and technology.

But eliminating interstation interference is less about the quality of
filters and more about station layout and grounding techniques.  It's about
brute force power line filters or (preferably) completely separate
power/ground islands for each station.  When the issues of RF floating on
the power and grounds of each station have been resolved and there is
sufficient separation between stations, no cross-band interference is too
severe for any of the brands of filters.  But when there is no separation of
power and ground between stations, or when the physical proximity of the
operating positions and antennas is unmanaged, no amount of filtering seems
to help.

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