[Top] [All Lists]

Re: [CQ-Contest] Bandpass Filters

To: "cq-contest reflector" <cq-contest@contesting.com>
Subject: Re: [CQ-Contest] Bandpass Filters
From: "Dave Hachadorian" <K6LL@ARRL.net>
Date: Fri, 19 Oct 2007 17:36:42 -0000
List-post: <mailto:cq-contest@contesting.com>
I use a pair of Dunestar 600's and they have been totally 
reliable in cw, ssb and rtty for many years. My friend 
across town has a pair of ICE units, so I am familiar with 
those also. As far as I can see, there are three advantages 
to the Dunestar units, compared to ICE:

1. The signal path in the ICE multiband units goes through 
12 sets of relay contacts, 10 of which are in the relaxed 
position. I have seen instances where received signals drop 
out and one has to "whack the box" to get them back again. 
The Dunestar unit signal path has only two relay contacts, 
both of which are in the energized position.

2. Ten meter capacitors in the ICE units get very hot at 100 
watts, and I have seen them fail repeatedly. Failures have 
also been reported on this reflector. We replaced my 
friend's 10 meter capacitors with "snubber" caps obtained 
from Mouser, and they have survived for a couple of years 
now. They do get hot enough to boil spit.

3. Dunestar's support is excellent. I have seen reports on 
the reflector where people sometimes have difficulty 
contacting ICE. It took a long time to get replacement caps 
from ICE, but eventually they did provide them at no charge. 
Capacitor values are not in the ICE literature, and it took 
us quite a while to get that data from ICE.

The ICE units do have one advantage - they come with a 
built-in manual bandswitch. If you want to switch the 
Dunestar units manually, you will have to build a bandswitch 
for each unit. What you really want to do though is automate 
the bandswitching to follow the radio, so a manual 
bandswitch is not really required.

Also, as I remember, the ICE units have LED's showing which 
band is activated. With the Dunestar units there is no such 
display. I always check the Dunestars with a mechanic's 
stethoscope ($6 at Harbor Freight) before a contest to be 
sure the relays are clicking when I change bands on the 

Regarding out of band attenuation, I haven't seen any 
significant differences between the two units. They will 
both allow high power so2r operation with closely spaced 

Dave Hachadorian, K6LL
Yuma, AZ

----- Original Message ----- 
From: "Philip Leonard WVØT" <leolists@seidkr.com>
To: "reflector cq-contest" <CQ-Contest@contesting.com>
Sent: Friday, October 19, 2007 4:32 PM
Subject: [CQ-Contest] Bandpass Filters

> Dunestar or ICE or ????
> Which do you use and/or recommend for SO2R?
> Thanks, Philip WV0T

CQ-Contest mailing list

<Prev in Thread] Current Thread [Next in Thread>