Survey of Band Pass Filters (Long)

Jastaples at Jastaples at
Wed Jul 19 10:53:48 EDT 1995

Boy, did I ever kick open the flood gates. I didn't expect the number of 
requests for this filter survey that have come in... I am posting it to 
the Reflector to save time... thanks for the resopnse.


Here is a compilation of the comments I received to my question regarding 
the relative merits of the Dunestar and ICE multi-band switched band pass

Dunestar Model 600 - Multi Band Remote Switched Bandpass Filter


"... we've been using a couple of the Dunestar 600's with TopTen Devices 
decoders ... since last season. Once we got a few teething problems 
behind us, they seem to work very fb, indeed. We also use individual ICE's 
... but the Dunestar is maximum convenience. ... you can get CT (or TR) to 
switch the bp filters for you.  One less thing to worry about."

"It's simple, Dunestar delivers and they work. I talked to a local
of ICE and he cannot get any of the ICE autoswitch filters delivered to
even though he has them on order for 6 months..."


"I've got 2 of the Dunestar 600's.  They work fine, but I dont recommend
running 200 watts thru them unless things are perfect.  I've burned up caps 
in several sections on both of them running my FT1000 barefoot into SWR's 
higher than 2:1.  WARNING!  DO NOT USE a tuner between your radio and the 
filter (ie. a built-in tuner)!  This exacerbates the problem.  Of course, if 
you just use it on the transmit side or into an amp, you'll be fine."

"I like the Dunestar 600 I bought... , but we seem To fry a section every 
contest, largely due to operator error in not manually switching the band. 
It can be hooked to a bandswitching box to have it auto-track band changes, 
but we use different rigs each time, so have kept manual band switch. The 
problem is if you XMIT on wrong band, it usually fries one or two capacitors 
in the wrongly selected section. The filter is NOT SWR forgiving on any band,

correctly selected or not. It is represented to handle up to 2:1 SWR, which 
in my book is not very forgiving under contest conditions. This time when I 
returned it for repair, I asked for a set of baggies with replacement 
capacitors for each section so we can repair it ourselves."

"The earlier Dunestar seems limited in power handling capability, and I'd
worry about the model 600 at 200 watts, but with a 100 watt exciter things 
are FB."

ICE Model 419 - Combination Bandpass Filter


"I have 2 of the ICE Model 419's and my overall impression with them is very
good. On the plus side:
* Very nicely constructed. Hefty cabinet and copper pc-board base.
* Indicators and controls are big and nicely laid out.
* Enough space inside to add the TopTen Band Decoder
* Fairly easy to repair if needed."

"I've also used the ICE individual filters and think they're great. Did not 
buy Dunestar's, ... because he didn't rate them at 200W (I have an
FT-1000).  The ICE units are certainly more "robust", without

"I havent used the ICE unit personally, but the one BIG advantage to it is
that it has a manual control switch on the box!  The Dunestars require an 
external switch box or auto band relay driver interface.  This could be very
inconvenient for DXpeditions, FD etc.  Also, the ICE unit is less expensive."

"I have the ICE set and I bought two Dunestar 600s for my ICOM rigs. I don't 
have the equipment to objectively measure the differences.  I would
assume that the physical separation offered by the ICEs would make them
"better" until you consider the effect of any automatic or manual siwtching
arrangement. ... I wanted something more automatic, and with a Top-Ten box 
for each rig things are indeed automatic.  The isolation seems OK, but I'm 
not able to objectively measure this.  I suspect my antenna proximity is a 
more important factor. I have also purchased some ICE receiver front-end 
protectors (which are a couple of transformers and a light bulb in a box) 
to keep from blowing up my RX again."

"The ice is built much better - not only the housing but the guts, I have
seen the D-Star multiband unit crap out, but not the ICE (yet, anyway). I 
like my ICE very much.  We used the three ICE filters during our 3 TX 
multi-multi for the CQWPX, there was very little intrastation interference, 
we didn't use any stubs phase will be to add stubs to the
filters - I haven't got mine
automatically following the rig as it changes bands as of yet , but that too
is coming!"


"On the minus side:
* ICE is slowwwwwww to fill orders. If you want it for CQWW, order NOW!
* If I recall, they're only rated for 200w. Not a big deal for most folks,
  but if you accidently load up 250w into the wrong filter...Poof!
* In the past they varied the pinouts on the rear DIN connector. This
  proved fatal to a friends FT-890. Get a schematic! They didn't include

If your going to control them via a band decoder, you need to tell them
which one you're going to use. Some use positive activation, other use
negative.  The LEDs won't work if you mismatch."

"... I have a pair of the ICE filters. I ordered them a few weeks before SS 
last year and was told about 3 weeks delivery.  After about a month I started

calling them, and each time they said my filters would be shipped within a 
week.  Several months later I still had not received them.  In February the 
charge for the filters showed up on my Visa statement, but still no filters
delivered.  They acknowledged they had charged me without shipping the
merchandise and gave me the same line I had heard a dozen times
before, that they'd ship that week.  A month later still no filters,
in spite of weekly promises that they'd be shipped pronto.

To make a long and frustrating story short, I finally received the
filters some time in May.  I checked them out and found they both had
miswires that caused the band indicator LEDs to not function properly
when using the remote programming connector.  Additionally, one of the
filters was not functioning on 20m.  The paint finish on one of the
cases was apparently applied over grease and rubbed off in a large
area from my limited handling.  I returned both filters for repair and
received them back in good working order in June.

My experiences with ICE are similar to those of another local here who
waited even longer for a preamp, and who also bought a tvi filter that
was DOA.  He waited over a month for the filter to be repaired.

>From what I have seen of several ICE products, they appear to be
reasonably well designed, but their quality control and customer
service is abysmal.  I would only buy from them as a last resort, and
be prepared for the worst."

>From Steve Fraasch <sfraasch at ATK.COM>  Wed Jul 19 19:31:00 1995
From: Steve Fraasch <sfraasch at ATK.COM> (Steve Fraasch)
Date: Wed, 19 Jul 95 11:31:00 PDT
Message-ID: <300D502D at msm.ATK.COM>

Someone replied via the reflector that he had a large set of tower 
insulators, but did not sign his e-mail.

Remember, on some systems the origin of reflector messages is: "Owner - CQ - 
so it's impossible to know unless you sign the message and give your e-mail 

Anyways, I am certainly interested in your insulators.  Please reply direct 

sfraasch at


Steve, K0SF

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