I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

I had this problem myself once. RF was getting in through the
Microphone connector. ferrite on the Mic cable corrected it for me.

Good luck,

Bruce , N1RX

On Wed, 13 Aug 2003 15:08:25 +0100, Richard C. Ferryman
wrote:

I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

I had this problem myself once. RF was getting in through the
Microphone connector. ferrite on the Mic cable corrected it for me.

Good luck,

Bruce , N1RX

On Wed, 13 Aug 2003 15:08:25 +0100, Richard C. Ferryman
wrote:

I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

I had this problem myself, years ago. Turns out, the RF was getting in
through the Mic cable. If you still have the mic connected, even
though you are putting your data in through the back, try
disconnecting the Mic, or using ferrite on the mic cord right at the
front panel connector. Good luck.

Bruce, N1RX

On Wed, 13 Aug 2003 15:08:25 +0100, Richard C. Ferryman
wrote:

I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

I had this problem myself, years ago. Turns out, the RF was getting in
through the Mic cable. If you still have the mic connected, even
though you are putting your data in through the back, try
disconnecting the Mic, or using ferrite on the mic cord right at the
front panel connector. Good luck.

Bruce, N1RX

On Wed, 13 Aug 2003 15:08:25 +0100, Richard C. Ferryman
wrote:

I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

Richard C. Ferryman wrote in message . ..
I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

What kind of antenna and feedline are you using? MK

Richard C. Ferryman wrote in message . ..
I have been struggling for some time to get RF out of the TX audio on
a TS-440SAT when in data mode. I have ferrite blocks everywhere;
power lead, 13 pin audio lead, aerial feeder, data control cable.
Sometimes I seem to cure it then it returns. Checked every grounding
screw in the rig, checked all internal connectors. Fitted isolation
transformers on audio. It stillcomes back. Does anyone know where
the weakness is in this rig?
Richard G4BBH

What kind of antenna and feedline are you using? MK

I just disconnected every multi-pin connector in the rig that carries
audio or rf and wiped the pins and applied some 'switch cleaner'
lubricant. I also removed several screws around chassis components
and antenna connector and cleaned the mating surfaces with a glass
fibre brush, wiped with same lubricant and refitted screws. The rig
is stable again. Seems that the TS-440 must have some horrendous rf
curents circulating around the chassis that can't tolerate a few
milliohms of contact resistance. Now we'll see how long it stays
stable!

Oh for a solid cast aluminium chassis.

73 de Richard G4BBH

I just disconnected every multi-pin connector in the rig that carries
audio or rf and wiped the pins and applied some 'switch cleaner'
lubricant. I also removed several screws around chassis components
and antenna connector and cleaned the mating surfaces with a glass
fibre brush, wiped with same lubricant and refitted screws. The rig
is stable again. Seems that the TS-440 must have some horrendous rf
curents circulating around the chassis that can't tolerate a few
milliohms of contact resistance. Now we'll see how long it stays
stable!

Oh for a solid cast aluminium chassis.

73 de Richard G4BBH