Vernall wrote:

Tom G3OLB,

> Talking of TS-850s, does anyone know why my TS-850 changes gain at
> 500.000 KHz? Seems like an attenuator is switched in above 500 KHz. Is
> there a mod to defeat it?

The TS-850 is manufactured with an attenuator for the MF AM broadcast band
(included within that band pass filter).  The attenuator is made from
surface mount resistors, on the underside of the PCB, so it is a fairly
tricky job to rework.  If you do a web search for TS-850 mods, you will find
a text and figures as to how to remove the attenuator.

Yes,
 that is typical for Kenwood, probably they fear their rigs get saturated in the
MW band.... when modifying my TS-950SDX to improve its sensitivity in the LF
band, as described in a past message, I eliminated that T-network attenuator.
In my case it was rather easy, as Kenwood had kindly provided two test
pins (???), just before and after the attenuator. So all it was needed was just
a jumper. It looks like they had foreseen the need to bypass it.
I have noticed no ill effects after its bypassing, probably in Japan they have 
much
stronger MW transmitters than here :-)

73  Alberto  I2PHD