CHIRP

Yes, it is excactly as you describe. [B] does not transmit [A] Does (and yes, real RF is generated).

Would it not be possible for chirp to set a known "out of range frequency" as the TX for this model in order to disable transmit? I am sure some work around (or hack!) must be possible to acheive the desired outcome. Should each model not have work around coded into CHIRP for an important feature like this. Radios that can not handle an RX only channel in the firmware could be programmed with a suitable stupid or illegal value? Just comment it "quirks" in the code ;-)

Also Duplex "off" is unhelpful, could the GUI have "NO_TX" or "RX_ONLY" or some other meaningful text in the pulldown instead of "OFF", I had to quite a bit of googling to find the solution.

To my personal way of thinking "duplex off" is simplex, IE normal operation.

Thanks,
Jon

Jon,

Yes. I had a friend do some testing with a frequency counter. When the [A] display is selected, there are spurious emissions around 129.200 MHz irrespective of programmed frequency. When the [B] display is selected there are no emissions.

Unlike all of the other Baofeng radios, which requires the RX frequency and TX frequency to be stored in each memory (no shift and no offset), the UV-B5 requires the RX frequency, the shift direction and the offset amount to be stored in each memory.

CHIRP inhibits the TX frequency in exactly the same way that the Baofeng software does. It sets the shift direction and offset to put set the TX frequency to an "out of range frequency". The RX frequency is shifted in the - direction offset by the RX frequency which puts the TX frequency at 000.000 MHz (about as out-of-range as you can get).

For the fun of it, I used the Baofeng software to program a TX inhibited memory channel. The behavior of the radio was exactly the same as if it was programmed with CHIRP. The fact that it only works as desired on the [B] display is a problem with the hardware, not CHIRP or the OEM software.

CHIRP is open source. If you are so sure there is a workaround for this feature, you are welcome to figure out what that workaround is and implement it.

As for Duplex = "off", that is a whole separate issue. I would suggest that you join the developer mailing list and start up a discussion.

Jim

_"there are spurious emissions around 129.200 MHz irrespective of programmed frequency"
_
Ahh ... I do see one thing I have wrong this end (sorry, me bad). I purchased this as a UVB5 but reading the label on the back of this handset it is in fact a UVB6 and I had failed to notice !

I got out the spectrum analyser, lovely clean results so far. I even looked at exactly 129.2Mhz and I see nothing interesting other than the noise floor so my guess is that is a model specific problem with the B5 ?

"Unlike all of the other Baofeng radios, which requires the RX frequency and TX frequency to be stored in each memory (no shift and no offset), the UV-B5 requires the RX frequency, the shift direction and the offset amount to be stored in each memory".
OK, I understand - seems a slightly crappy way of doing it (Beofeng firmware authors that is, not CHIRP !)

I had a play with the sofware and have had no joy so far. Unless a TX enhibit bit is floating around in the channel record then I guess I cant see another way to fix it. Have all the bits in a channel record been indentified?

+As for Duplex = "off", that is a whole separate issue. I would suggest that you join the developer mailing list and start up a discussion.
+
OK, I will see if I can raise that.

Thanks for your help.
Jon