[TowerTalk] Bandpass filters - ICE vs Dunestar

[David Hachadorian]

----- Original Message ----- 
From: "Pete Smith" <n4zr at contesting.com>
To: <towertalk at contesting.com>
Sent: Monday, January 31, 2005 3:30 PM
Subject: [TowerTalk] Bandpass filters - ICE vs Dunestar


> Judging by their published specs, the Dunestar 600 
> bandswitched bandpass filter appear to be usefully better 
> than the ICE 491 unit.  Can anyone who has used both 
> comment on whether this is true, and whether $110 per 
> filter is worth it?  Are there other considerations?  I 
> will be using band decoders to control the filters, so the 
> lack of an external controller for the Dunestar is not a 
> factor.

I have the Dunestar, and I have helped my buddy W7WW with 
His ICE 491, so I am familiar with both.

The Dunestar can be rewired for either +12 volt band 
selection, or ground lead band selection. The ICE only 
supports one type (I think it's +12, but I'm not sure). 
Depending on the output of your band decoder and other 
accessories, this may or may not be of concern.

W7WW has twice blown caps in his ICE 10 meter filter. I have 
seen postings on the reflectors of other people who have 
also blown the 10 meter caps, so something is marginal 
there.

In the ICE design, the signal path goes through 12 sets of 
relay contacts, 10 of which are normally closed. W7WW has 
complained about intermittent signal dropouts on receive, 
where he either has to physically smack the box, or transmit 
one DIT to break through what is apparently an insulating 
film on one of the normally closed relay contacts.

W7WW and I both have all of our antennas in close proximity, 
and the ICE and Dunestar both provide enough isolation for 
so2r at high power.

Dave Hachadorian, K6LL
Yuma, AZ