[ICOM] AT500 problem on 18 and 24 Mhz

[Bert Almemo]

Hi Gary,

Thanks for info. I'll try your suggestions and report back.

73 Bert, VE3OBU 

-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of Gary Fiber
Sent: Saturday, January 07, 2006 11:30 AM
To: ICOM Reflector
Subject: Re: [ICOM] AT500 problem on 18 and 24 Mhz

Bert,

The AT-500 can have a couple of preset positions. Many times when you do the
preset the capacitors will be almost fully open. So you might remove the top
and have a look. The caps should be a bit more meshed.
I used to tell people to connect a known dummy load and do the presets into
that to get to a known starting place. Then reconnect the antennas and do
over the presets. I also recommended they use a SWR meter not the LED's
within the unit. It worked for many operators.
Remember the AT-500 will show you a faulty antenna pretty quickly. I once
had an antenna that would be fine and then go into trouble after a few
minutes of transmitting.
Up on inspection one snowy evening on the tower top I found the coax braid
to be corroded to a very black color. Replacing the coax solved the problem.

Hope some of this helps

Gary K8IZ

At 07:13 AM 1/7/2006, you wrote:
>I have problems with my AT500 on 18 and 24 Mhz bands.
>
>This is the setup: IC-765, IC-2KL and AT500. 3 antennas are connected 
>to the AT500. Ant1 - yagi for 14/21/28 Mhz,
>Ant2 - Carolina Windom for WARC bands+7+3.5 Mhz, Ant3 - Inverted L for 
>1.8 Mhz.
>
>When switching the trx to 18 and 24 Mhz bands, AT500 in AUTO positon, 
>the signal/noise drops drastically and only very strong stations can be
heard.
>It seems like the AT500 is not tuning properly.
>
>If I manually switch the AT500 to another band, trx is still on 18 or 
>24 Mhz, using the Windom, e.g. 3.5 Mhz the signals are back to normal 
>or much higher than when in the AT500 is in the AUTO position.
>
>I have gone through the preset procedure and checked all connections 
>and everything seems to be OK. Still, the AT500 does not tune properly 
>on 18 and
>24 Mhz, which are the only two bands where you have two bands in the 
>same band switch position, i.e. 18/21 and 24/28. Any suggestions would 
>be much appreciated.
>
>73 Bert, VE3OBU
>
>----
>Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net Icom 
>Users Net: Sundays, 1700Z, 14.316 MHz Icom FAQ: 
>http://www.qsl.net/icom/

Gary Fiber K8IZ
GROL PG-19-6691
Washington State Resident


----
Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net Icom Users
Net: Sundays, 1700Z, 14.316 MHz Icom FAQ: http://www.qsl.net/icom/