Date: Thu, 20 Jun 2013 12:34:08 -0700
From: Jim Brown <jim@audiosystemsgroup.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Control of ICE 419A Bandpass Filter
On 6/20/2013 12:15 PM, Allen Brier N5XZ wrote:
> I will be getting an ICE 419A Bandpass filter soon at a good price. Wondering
> what is the best way to control it with a K3. Suggestions?
Sorry to be the bearer of bad tidings, but the "good price" for ICE
419-series filters is free. Several common problems.
#1, the relays get very flaky, and are hard to replace. Spraying them
with the "right" contact cleaner is about the best you can do.
#2, the filters don't handle anything close to rated power, and even
relatively small SWR (1.5:1) makes it worse. It's common for them to
fail (blown capacitors) with 100W. They'll probably be OK at the 40-50W
level needed to drive an amp.
#3, even when they're working they're not great filters.
#4, every ICE filter I've ever bought, new or used, was out of alignment
(high SWR, tuning not right). A filter that is out of alignment is more
likely to fry.
73, Jim K9YC
## I have the ICE 300 watt HP filter that has a cut off of 1.7 mhz. Right
out of the box...
and into a dummy load, the swr was a bit flaky on 80m. On 160M, with 200w
cxr applied, it was
only 150 w on the output of the ICE HP filter. The caps were fried !
Caps were replaced with several
lower value caps in parallel. It was not a peak V problem either. It was a
current handling issue with the caps.
## at the time we had 10 kw AM stations on 900 khz and also 1070 khz.....and
also a 50 kw station on 1200 khz.
All 3 of em were on small islands just off shore 2 miles from me. The ICE
filter had about 15-18 db attenuation at 1200 khz...
and 50 db at 550 khz.
## all the caps had to be replaced as described.... just so it would handle
200 w pep on ssb/ cw...into a flat swr.
I looked at their bandpass filters and passed on em, just not robust enough for
me.
Later... Jim VE7RF
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