SSB Ground Plane - Advice?

Duane Siegfri

We're having issues with our ICOM M802.  It won't transmit at all.  Another cruiser (electronics engineer) checked it with an SWR meter and said the antenna reflectance was off the charts.  I understood that to mean the ground plane (counterpoise) was not "present" to the radio.

We are receiving Chris Parker, with a lot of static, between FL and the Turks & Caicos.  We could not get him in Sint Maarten.

We checked the conductivity of the ground wire and it was fine, so apparently that's not an issue.
We also checked the mic on another set and it was fine.
We checked all the connections, and they were fine, no corrosion, shiny and tight.
We opened the antenna tuner and it looked good, no corrosion.  We could hear the tuner tuning.

I'm wondering if the lack of a counterpoise could have shorted something in the radio that is causing the lack of transmission?

What could be causing the extreme reflectance on the SWR meter?

Any recommendations for a radio tech in Ft Lauderdale?

ICOM's manual said absolutely not to use round wire for the ground connections, which is what is on my boat.  If you have an Amel installed SSB, is the ground wire flat copper ribbon or is it round wire?

Wanderer, SM#477

Alan Leslie

Hi Duane,
Lack of a ground connection can cause crazy SWR readings.
Lack of a ground connection will make it impossible to transmit.
Lack of a ground connection doesn't affect your ability to receive.
Faulty coax cable between the radio and the tuner can cause high SWR readings.

You need to check that there is a low impedance path from the antenna tuner ground to the sintered bronze plates on the rudder skeg.

The best ground connection between all components is flat copper strip, but wire will work as long as it is multistranded and low impedance.(we have wire from the radio to the tuner to the ground plate connection in the lazarette, and it works fine).

Elyse SM437