[South Florida DX Association] those new Chinese Wouxun HT's...FYI...info from one of the commercial groups.

[Mike Williams]

> A group I have some association with was looking at Wouxun radios for
> a Part 90 VHF& UHF application (analog) along with amateur
> applications. The radios have been rejected due to the inability to
> individually set CTCSS, DTMF, and audio deviation levels (1550 Hz
> CTCSS deviation in a 2.5 kHz audio deviation NBFM application).
> They're now working with higher tier radios.


>
Also a few hams on another popular list are seeing issues with DTMF on 
those. Turns out the radios do a kind of 'ping' at the beginning of each 
transmission, causing 20-30 KHz deviation spikes. And each digit pressed 
causes a similar spike. One thought is that they are just coupling the 
speaker audio to the mic for DTMF, instead of actually injecting into 
the transmitter audio circuits. (Someone found that DTMF decoding on the 
other end varied with volume setting on his radio.) DTMF as low as 1.8 
KHz and as high as 4+. In any case, it appears there is little to no transmit deviation limiting. Plus the CTCSS level problems you're seeing. ugh.


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73 de W4DL   Mike