[ICOM] ICOM 746PRO local image problem

[wa4tuk]

My IC-746 (not pro) developed strong birdies at regular intervals. This 
was noticed just after turn-on.  I was so surprised I tried to receive 
these with another receiver only to finally determine they were all 
internal to the 746.

I really thought this was the end of the unit with the synthesizer or 
CPU or something needing a level of repair not likely by myself.

A power cycle made no difference but a complete factory reset fixed the 
problem to my great relief.

Page 81 in the 746 book. I don't know the exact procedure for the 746pro.

For the 746..."While pushing in [F-INP] and [M-CL], push [POWER]	to turn 
power ON."   quoted from the IC-746 FAQ

Let us know if this helps.

Pat
wa4tuk



Gregory W. Moore wrote:
> GE, All,
> I own an Icom 746PRO, and it seems to have developed an annoying problem 
> (S??) with the synthesizer.
> 
> I have CW image freqs currently on 6800.0, and multiples of the same
> as well as both 23 and 32 MHz and fractional harmonics of the same.
> (6.800USB happens to be a SHARES nite PACTOR BBS freq.
> 
> There seems to be a 600Hz multiple on an audio spectrogram, peaking on 
> the selected freq, as well as decreasing harmonics every 600Hz up and 
> down the freq scale.
> 
> I also seem to have lost a great deal of selectivity/sensitivity in the 
> front end, and tuning seems to pose a problem. There seems to be a
> "hangup" in tx/rx switching, especially in digital modes such as PACTOR, 
> when audio goes from normal to distorted going thru several TX/RX
> cycles.
> 
> These carriers seem to be "digital hash" and are indeed, binary 
> multiples of eachother...
> 
> Anyone in the group has had this problem?? any solutions, and possibly 
> an  "at QTH" repair before I ship the whole shebang to ICOM for 
> evaluation and service.....
> 
> OPNOTE: This is NOT the CW sidetone, however, the CW sidetone is 
> significantly diminished at these particular freqs.  I have chosen
> the few I mentioned as a starting point, however, I have no doubt that 
> other image freqs exist as well, and have to originate in the rig since 
> it makes no difference if the antenna is terminated in a 75 ohm load or 
> simply disconnected.  There is also static!! on the 2M band, which 
> absolutely shouldn't exist...
> 
> I have been driving myself nuts for a while with this problem,
> the xcvr isn't that old, around 1993 vintage, and has apparently 
> developed this problem only recently..
> 
> 73 de Greg "GW" Moore WA3IVX/NNN0BVN