Yaesu Transmit Problem

[KF2FK]

I seem to be having a problem with my FT-897d. It does not transmit on 12 or 10 meters. The transmit light turns red. There is no movement on the power meter or SWR meter on the radio and on my MFJ tuner. The Radios modulation meter does move. All other bands function normally. I tried to reset the radio using HOME + Power ON. Any Ideas would be greatly appreciated.

Thanks

Mike

[n8yx]

Was anything recently changed within the rig, or did the problem just happen out of the blue?

[KF2FK]

The only thing that I changed was the radio's spot on the desk. I have not been on 10 meters in a few months. I was setting up 10 for my son who is a tech so he could work the Pentagon Special event this afternoon, and I noticed I could not tune up on 10 because I was not getting any power out. I tried AM and FM. I reset the radio with out any change. All other bands work fine.

[n8yx]

From the symptoms you describe, it sounds like something is amiss with the BPF circuit and its feedback signalling to the CPU.

Is there an external ATU or other device connected to a rear-panel accessory connector than has band-decode data present? The act of shuffling it around may have dislodged something.

[KF2FK]

Yes there is a CAT cable connected to the radio connected to the serial port on a PC. I will unplug it and try resetting then.

Thanks, I'll let you know what happens.

[KF2FK]

Removed the CAT cable, Reset and still the same problem. I did notice there is no click when keying up. So there must be a relay that is not working for those 2 bands.

[n8yx]

Removed the CAT cable, Reset and still the same problem. I did notice there is no click when keying up. So there must be a relay that is not working for those 2 bands.

Are you comfortable with servicing your own equipment - and do you have a service manual?

If 'yes' to both of the above:

Open the rig's case and locate the control lines which go to the LPF/BPF board. Verify voltages on each filter range...particularly the upper segment. (For that matter, identify the accessory connector pin which should be active on 12/10M and measure the voltage when the bands are selected.)

See voltage?

If so - you may have a bad relay. Without looking at a schematic, I'm not sure what else is controlled by the CPU with regards to band logic.

If there is no voltage at the control line...something might be amiss in the wiring harness, or with the CPU assembly itself.

[KF2FK]

I don't have the service manual, but I do notice the radios voltage display dropping from 13v to about 10v when keying. Would that also indiacte a bad relay?

[n8yx]

I don't have the service manual, but I do notice the radios voltage display dropping from 13v to about 10v when keying. Would that also indiacte a bad relay?

Does it do so on every band - and what of the supply you're using? Adequate amperage?

[KF2FK]

I'm using an astron 20 amp supply, it only does it on those band segments

[n8yx]

I'm using an astron 20 amp supply, it only does it on those band segments

Interesting.

Have any way to monitor the current into the rig (an inline ammeter)?

Observe the current draw in RX on 12 or 10 then switch to TX - with mic gain and carrier-level controls at minimum, of course. Check the current. Now repeat the experiment on a band besides 12/10. See any difference?

[AD1U]

IS ANY ONE KNOWS HOW TO FIX MY YAESU FT 5100 AUDIO THAT IS SO WEAK, LOW AUDIO. THANKS

[W6GQ]

Removed the CAT cable, Reset and still the same problem. I did notice there is no click when keying up. So there must be a relay that is not working for those 2 bands.

Did you try the relay cleaning feature?

I do not know if it would help, but it cant hurt?

Press and hold the "DWN" and "UP" keys simultaneously and turn ON the transceiver. All band relays will start "clicking" and "RELAY CLEANING" is showing at the display.

Let us know.

[KA1MDA]

Just a hunch: Have you tried keying on those bands into a dummy load? Could be an off chance that you're getting RFI into the power supply on those bands, causing it to fold back, which in turn causes the radio to stop TXing. This could be happening so fast that the radio would appear to not transmit at all.

Also try setting oputput power to minimum level and see if TX works on those bands. If TX is ok at low power, but problem comes back on high power, would also point to an RFI issue.

Tom, KA1MDA

[N5NPO]

IS ANY ONE KNOWS HOW TO FIX MY YAESU FT 5100 AUDIO THAT IS SO WEAK, LOW AUDIO. THANKS

Have you got another mic to try on it?