[Top] [All Lists]

Re: [TenTec] Omni VI Plus (564) 10 meter xmit dead

To: tentec@contesting.com
Subject: Re: [TenTec] Omni VI Plus (564) 10 meter xmit dead
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
Reply-to: geraldj@storm.weather.net,Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Fri, 14 Dec 2007 14:02:44 -0600
List-post: <mailto:tentec@contesting.com>
On Fri, 2007-12-14 at 11:51 -0800, Peter Inskeep wrote:
> As last weekend's 10 meter contest started I discovered that my Omni VI + 10 
> meter transmit is "dead."  The receive may be diminished as well, but I am 
> not sure of that. I quickly switched to another rig.
> When the rig is turned on from cold, ie., power supply turned off until rig 
> turned on, I get about 40 watts on both the internal meter, and on my tuner's 
> meter.  This quickly drops to virtually zero, within seconds.
> All other bands work fine.  All four sections of the 10 meter band are dead.  
> Ie., 28.0 to 28.5, 28.5 to 29.0, etc.
> I have pulled the rig apart.  I suspect that the problem is on the Xtax Osc. 
> - L.O. Mixer board (81595).  This board is located in the box under the 
> 81595SM and 82870 boards on the top left side of the rig.  It contains the 
> band crystals and a whole bunch of switching diodes, among other things.
> Thus, it is almost impossible for me to test anything with the rig running, 
> as I have to remove those two boards and the aluminium plate to get at the 
> Mixer board.
> I suspect the L.O. Mixer board because it seems to be the one place where 10 
> meter signals are completely separated from other band signals.  In fact, I 
> am most suspicious of Q4 and/or Q5 on that board.  I will replace them to see 
> if that does it.
> I have checked diodes, in circuit, until my eyes are crossed.  I have checked 
> solder traces until my eyes are recrossed.  I've found nothing that looks 
> bad, and nothing that does not check continuity with my vtvm.  
> Having bored you will all of the above, if you are still with me, I have two 
> questions.
> First, has anyone had the same symptom on their Omni VI Plus?   If so, can 
> you suggest a fix.  
> Second, is there some other circuit where all four of the 10 meter circuits 
> are separate that I have not been able to discover?
> I have not pulled the front panel off to see if the 10 meter button is 
> "broke."  I think not because, first, it enters the "9" digit without fail.  
> Second, it does kick in 10 meters when the rig is cold, and the display does 
> go to 10 meters.
> Finally, I know that the intelligent thing to do is to box it up and send it 
> to Ten-Tec.  They will not only fix this problem, but reallign it and make it 
> better than new.  If the two transistor replacements don't do it, and no one 
> on the reflector has a solution that I can implement at home, I will send it 
> back to Ten-Tec after the holidays are over and UPS is back to moving cartons 
> instead of chucking them due to the holiday rush.
> I am not a frequent poster to the reflector, but I do monitor it, so, if you 
> can offer any suggestions, I will be most appreciative.  My XYL's solution to 
> this is to send the rig back to Ten-Tec in trade for an Omni VII.  Not a bad 
> idea!
> Thanks,
> Pete, no2d.
Band pass filters and their switching are probably shared.

73, Jerry, K0CQ

TenTec mailing list

<Prev in Thread] Current Thread [Next in Thread>