FW: [ICOM] AT500 problem on 18 and 24 Mhz

[Bert Almemo]

Hi again Gary,

I removed the top of the AT500 and had a look. Checking out the jumpers from
the switch to the antenna connectors reveals that there are no jumpers from
21 and 28 Mhz to ANT2 connector where the windom used on 18 and 24 Mhz is
connected. It seems I've been using the yagi for 14/21/28 on ANT1 to work on
18 and 24??? With bad results!!

This is embarassing and confusing. I thought I connected all the jumpers as
per instructions. 

So how do I get the windom on ANT2 connected to the switch position 21 and
28? Is it as simple as just putting in a jumper from ANT1 to ANT2 or...?
Probably not as the yagi and the windom work on the same bands between 14
and 28 Mhz. This is confusing?????? 

Do I need a separate coax switch for the yagi and the windom connected to
ANT1 where I connect all the jumpers from the band switch except for 1.8
Mhz?  Why didn't they design the tuner with separate bands for each position
on the switch?? Probably saving money?

What should I do to make this work?

73 Bert, VE3OBU



-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of Bert Almemo
Sent: Saturday, January 07, 2006 11:52 AM
To: 'ICOM Reflector'
Subject: RE: [ICOM] AT500 problem on 18 and 24 Mhz

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/

----
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/