[ICOM] IC-746PRO sensitivity and noise problems

[Gregory W, Moore]

GM to all in the group

I presently have an Icom IC 746PRO which I purchased back in 2002.  
Since I am a MARS op, it has the requisite mods required for such operation.

Now, I am experiencing whiat I believe to be both a lack of sensitivity, 
as well as a 60Hz harmonic on recieve all the way up thru 3500Hz.   This 
interference, of course, is much more noticible in AM mode, which I am 
using for troubleshooting purposes, as if I can get rid of the 
hum/interference whth AM mode selected, the performance on SSB will have 
taqken care of itself.

I had believed for a short time that the problem was due to an air 
conditioner, but I have since discovered that it is not eminating from 
this household.   Yhere also appears to be a general lack of
gain and sensidtivity which have gradually increased over time.

I have some wav files of the interference, as well as a  screen capture 
of the waterfall display on MixW qwich will show the interference, and 
to save transmission bandwitth, if anyone would like to hear/see the 
problem I will post them on my website so they can be downloaded, 
instead of tying up time on downloading large attachments via email.

If anyone has any ideas as to where I should be looking, I would be 
appreciative of suggestions.
I want to get this fixed before I put my longwires up, for there is no 
point in putting up a better,, broadband, antenna up with the noise 
problem  in existance.

I am running the 746PRO thru aqn MFJ -969 Versa-Tuner into a Gap Titan 
Dx vertical.  I know that this is not the optimum, setup for MARS ops, 
but I am still in the process of obtaining and erecting the requisite 
towers to create the endpoints for the dipoles, as well as squeezing 
everying in my lot size.

Again, any oideas will be appreciated

73 es tnx de Greg WA3IVX/NNN0BVN


-- 

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Greg Moore NNN0BVN PA
U.S. Navy-Marine Corps Military Affiliate Radio System (MARS)
Official Pennsylvania Area Website:
http://pages.prodigy.net/nnn0fbk/mars.htm
Official Northeast Area Website: 
http://www.navymars.org/northeast/index.htm
Navy-Marine Corps MARS: Proudly Serving Those Who Serve."
E-Mail (MARS) nnn0bvn at navymars.org
E-Mail (ARRL) wa3ivx at arrl.net
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