Yaesu FTA750 issue

[Bosi72]

To the owners of FTA750.
Could you please check your radio on 127.55MHz and let me know if you have (or not) the issue shown in this video, and if yes how did you resolve it.
https://youtu.be/d7u-5B8N5fU
It appears there is some sort of feedback loop triggering radio squelch on this frequency. So far, the other frequencies are ok.
Thanks

[Jhieminga]

It could also be something in your particular neighbourhood that is emitting some sort of interfering signal on that frequency. I would borrow another handheld and check whether it shows the same behaviour in that location on that frequency. Alternatively, try that frequency from another location (if COVID restrictions permit).

Do you get this behaviour at all times? Do you get this behaviour when using that handheld in flight?

[Bosi72]

It could also be something in your particular neighbourhood that is emitting some sort of interfering signal on that frequency. I would borrow another handheld and check whether it shows the same behaviour in that location on that frequency. Alternatively, try that frequency from another location (if COVID restrictions permit).

Do you get this behaviour at all times? Do you get this behaviour when using that handheld in flight?

Thanks for response Jhieminga.
Definitely not location related. Last weekend I flied to Leongatha YLEG which recently changed CTAF from 126.7 to 127.55 and that's how I noticed the issue. The video was taken 40nm away. Also my other Ham radio handheld doesn't have the issue.

I want to confirm whether the other Yaesu fta750s are having the same issue, eg design flaw, or is it related to my radio only.

Emails sent to seller and Yaesu.com, still waiting for response.

[hegemon88]

Hi Bosi72,

I have just read your post, tested my FTA750, and replicated the issue!

In my study room I get a lot of interference on all frequencies, either because of computers or some metal elements in the external wall. However, in other corners of my house I got silence on a number of other frequencies, and an interference similar to yours on 127.550. I am thousands of miles from you at the moment, near EPZP and EPZG airfields, if that helps.


/h88

[Bosi72]

Hi Bosi72,

I have just read your post, tested my FTA750, and replicated the issue!

In my study room I get a lot of interference on all frequencies, either because of computers or some metal elements in the external wall. However, in other corners of my house I got silence on a number of other frequencies, and an interference similar to yours on 127.550. I am thousands of miles from you at the moment, near EPZP and EPZG airfields, if that helps.


/h88

Thanks hegemon88 !
I took two more videos, one suspecting poor shielding, another triggering "the looping" with my other Yaesu ham radio handheld.

http://youtu.be/iiGV9RNBlHQ

http://youtu.be/pmAv-C8vt4M

[Forfoxake]

Interesting but I could not reproduce this in my FT-550L.

[Jhieminga]

Definitely not location related. Last weekend I flied to Leongatha YLEG which recently changed CTAF from 126.7 to 127.55 and that's how I noticed the issue. The video was taken 40nm away. Also my other Ham radio handheld doesn't have the issue.
Good to hear that you were able to eliminate those options. Seeing as hegemon88 was able to replicate the issue, I wonder what Yaesu will have to say about it!

[NineEighteen]

I have the same sounds from my unit on that freq/channel. Very interesting.

I'm in South London and on the fifteenth floor of a block of flats facing south, just to specify some location data.

[topradio]

It will be a version of what we used to call a 'birdy'. The radios local oscillator will produce harmonics of the frequency and occasionally these would co-inside with the receiver fundamental frequency and be strong enough to get into the circuitry and open the squelch. The cure was to move the interference away to another channel by changing the local oscillator to a different frequency and also move the intermediate frequency of the receiver to accommodate the change. This was often on single channel radios but modern synthesised multi channel receivers do this automatically as part of the design as they know which channels are going to be affected.

Having said all that, the noise on your video is an intermittent 'crunch' and if it was the local oscillator it would be a continuous smooth noise. However the principle will be the same, something, probably associated with the processor or it's clock, is radiating undesirable signals that will pop up on certain channels and is fundamentally a result of poor design which really doesn't surprise me with Yaesu products.

I would be interested if they get back to you with a fix.