[ICOM] ICOM_746PRO_ALC_PROBLEM

Thu Apr 12 23:10:34 EDT 2007

I rate the response below as a 4 star (out of four) posting.

Regards,
Dick - KA5KKT/4 

-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of Alan Zack
Sent: Thursday, April 12, 2007 10:35 PM
To: ICOM Reflector
Subject: Re: [ICOM] ICOM_746PRO_ALC_PROBLEM

I had the same problem using a 746PRO and an Ameritron AL80B amp.  Seems
there must have been a mismatch between the 746PRO and the amps input
circuits causing the internal tuner to do a quick (or maybe false) load into
the amp, even with the 746's TUNE button turned off.  The cure was to read
the manual on how to tune the input circuits for each band. In the case of
the AL-80B there are holes in the rear panel marked for each band, insert
the tuning tool and tweak for minimum SWR shown on the 746's meter with the
internal tuner turned off.
______________________________________
Alan Zack
Amateur Radio Station K7ACZ
Official USCG Auxiliary Comm Station
Las Vegas, Nevada, USA
Delta Rocket Quality Engineer, The Boeing Company, Retired Aviation Chief
Warrant Officer,  U.S. Coast Guard, Retired

----- Original Message -----
From: "George" <goofyham at highstream.net>
To: "Icom Mailman" <icom at mailman.qth.net>
Sent: Thursday, April 12, 2007 4:25 PM
Subject: [ICOM] ICOM_746PRO_ALC_PROBLEM

A friend asked me to help him try to find out why his 746PRO ALC cuts off 
his SSB transmission for the first second or two while the ALC drops down 
from 100%???
This only happens when we have it running into his Ameritron AL811 amp???
This does not happen when we hook up his backup 746-non pro rig???
The ALC on the pro seems to have a very slow decay time as compared to the 
non pro 746. Why does the pro ALC jump to 100% intermittently when used with

the amp. It's very annoying to say the least and rendered it useless.
Has anyone else experienced this?
thanks.
George  W2YJ
----

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