Rather then trying to follow instructions when changing bands it is much
easier and safer to use a band decoder to automatically switch the filters
and antennas.
John KK9A
To: "Tower Talk" <towertalk@contesting.com>
Subject: Re: [TowerTalk] blown 10m section of ICE419 again
From: "Keith Dutson" <kdutson@sbcglobal.net>
Date: Wed, 2 Oct 2013 20:23:28 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I have a pair of 419A and a pair of 419B. The A's have been to many
DXpeditions, installed behind Kenwood 480HX's (200W). The first problem
happened back in 2004 in Falklands (VP8WWW). We were working into a Hustler
vertical. The problem happened when the radio band was changed to 20M but
the 419 was left in 10M. It does not take long to heat up the caps when
this happens.
I have made repairs to all four units ovet the years. Ten meters has the
highest failure rate, but 15 and 20 have also been damaged.
Thanks to advice from Dave Hachadorian K6LL, I have replaced caps to
increase tolerance for off-band operating errors.
Another thing I have done is attach an instruction sheet to each unit to
help lower the chance for operator error. I have pasted the sheet below,
but it is from a Word document that is formatted better for printing. It
can be sent separately for anyone who wants it.
An even better solution is to switch bands automatically when the rig band
changes. I use the Bandmaster from Array Solutions to do this.
73, Keith NM5G
419 instruction sheet:
----------------------------------------------------------------------------
---------------------
ICE Bandpass Filter Model 419 Instructions
DO NOT TRANSMIT INTO THE FILTER UNTIL THIS PROCEDURE HAS BEEN PERFORMED.
This procedure applies to both models 419A and 419B. Max input power is 200
watts.
INITIAL SETUP
1. Connect the filter between the transceiver and tuner/amp/antenna.
Placing the filter after the tuner increases the risk of overvoltage. Use
of an internal transceiver tuner is not recommended, but may be okay if it
matches VSWR 3:0 or less.
2. Follow CHANGING BANDS procedure below.
CHANGING BANDS
1. Set the POWER switch on the filter to OFF.
2. Set the BAND switch to match the band selected on the transceiver.
3. Set the POWER switch on the filter to ON.
If the transceiver is on a band not covered by the filter, leave the power
switch off; this will bypass the filters.
***NEVER*** TRANSMIT INTO THE FILTER WHEN THE BAND SWITCH LIGHT DOES NOT
MATCH THE TRANSCEIVER BAND!
----------------------------------------------------------------------------
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