[ICOM] Question about the original 706

[Gary Fiber]

Icom HF transceivers do not meet the published specification without the 
preamp enabled. Thats the way they are designed. If you look in the owners 
manual there is always a * pointing you to a note that states with preamp on.
Other manufacturers run the preamp all the time and turn it off, I forget 
what they call that button but its not referenced as a preamp button.
I had seen this in the older Kenwoods and Yaesu's I could not say if the 
current products they build are doing the same thing.

The original 706 fan ran always and speeded up when the rig go hot enough 
to warrant that happening.
I seem to remember an end user modification to stop the fan in receive mode 
or slow it down a bit. Cooling was sacrificed by doing that mod however the 
fan did resume when the transmitter was enabled.
Yes the preamp was a bit noisy too on the original but otherwise worked ok.

Hope some of this helps.

Gary K8IZ


>The fan is always on.
>Sensitivity on 2m is ok.
>Without preamp, the rig is not hearing well. The preamp on the other hand 
>elevates the noise level a lot.

Gary Fiber K8IZ
GROL PG-19-6691
Washington State Resident