Misc; Are There Different Versions Of The Ic-746; Can I Operate 2M On Reduced Power; Where Can I Find Plugs For The Acc Connectors - Icom IC-746 Faq

8

Misc...

8.1

Are there different versions of the IC-746?

Yes, there are at least two distinct versions of the IC-746.
While most of the indications are circumstantial, one definitive piece of evidence are the two
different procedures for modifying the transmit/receive range.
Another definitive indication are the 2m differences between the U.S., Japanese, and
European versions. In Japan, the IC-746 has different auto-repeater offsets and is limited to
only 50w RF output. In Europe, the IC-746 does not transmit above 146Mhz and has no
auto-repeater offsets at all. There's also a version in Australia that is limited to 20/8 watts on
2m for FM/AM.
There are varying reports about the necessity of a microphone pre-amp when using Heil
microphones, leading some to speculate upon differences in the microphone input circuitry.
K9HFX was unable to generate DTMF with an HM-14 microphone; that might be related.
There isn't enough information yet to be conclusive.
Some rigs seem to have problems with the transistors that drive the LCD backlight, while
some do not. This might be due to a circuitry change, or a difference in assembly. The jury
is still out.
The only way the issue will be resolved conclusively is for someone to organize a data
collection effort to sort out these details by serial number. So far, no one has volunteered.
8.2

Can I operate 2m on reduced power?

Sure, just turn down the RF output power control (along the bottom front edge of the rig).
Too inconvenient? Then you could get inside and tweak the pots that control the RF PA
settings. There are 4 of them for HF, 6M, 2M and AM (R989, R991, R993, and R990
respectively). Refer to your Service Manual for details.
8.3

Where can I find plugs for the ACC connectors?

They are 7-pin DIN connectors (the old style AT keyboards used 5-pin Din). A couple (of
many) possible sources are:
Digi-Key
BUX CommCo
Your local electronics store probably either has them or can get suitable substitutes. For
example, most Radio Shacks have the 8-pin DINs in stock (#274-026). They are compatible
after you remove the center pin.
IC-746 FAQ
http://www.digikey.com/
http://www.buxcommco.com/
Page 90 of 113
2003-02-08