[ICOM] IC 725 Intermittant Transmit Failure

[Adam Farson]

Lee, Bruce,

Another possibility is that the LPL (DDS) is on the edge of unlocking. Try
aligning the DDS as described in the service manual. 

You can download the service manual here:

http://www.marcucci.it/english/download/index.htm

Cheers for now, 73,
Adam VA7OJ/AB4OJ


-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of Bruce
Sent: 19 October 2006 09:24
To: ICOM Reflector
Subject: Re: [ICOM] IC 725 Intermittant Transmit Failure

Lee,
When you go to Tx does the light on the front panel turn red?
If it doesn't you probably have a PLL unlock condition due to bad trimmer
cap or cracked solder around the LPL loop circuit. To confirm LPL loop try
going to 7.000 MHz freq and try and Tx then move up to say 7.150 MHz, do you
get Tx then?
Very hard to troubleshoot this way..
Bruce
At 07:43 AM 10/19/2006, you wrote:
>I have an IC 725 that intermittently (at an increasing frequency) locks 
>up and will not transmit rf when the PTT on different microphones is 
>pressed.  Relays click and the receiver switches, but no rf appears at 
>the output.  This condition can be eliminated temporarily by cycling 
>the radio off and then on again.
>
>The radio has had little or no use in the past ten years until 
>recently.  The symptoms maintain despite changing antenna systems, 
>microphones, and even power supply cables.  Nothing regains operation 
>(switching bands, randomly punching every front panel control, etc.) 
>except cycling the power switch off and then on.
>
>Any one know what the cause might be?
>
>73 de Lee
>KM4YY/8
>
>----
>Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net Icom 
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----
Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net Icom Users
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