I did a quick test only yesterday night at my FT-450 and here are the results:
500 Hz 40 W 1000 Hz 40-50 W 1500 Hz 40 W 2000 Hz 40 - 50 W 2500 Hz 20 W There is not at all such a big difference for the different tones even though it's for sure not a very even passband for the system soundcard + transceiver. I have to say, however, that I didn't do any precise measuring of the output voltage of the soundcard. This means that it is not correct to make any conclusion to the transceiver passband based on the above figures. 73 Juergen, DL8LE --- In digitalradio@yahoogroups.com, Sholto Fisher <sho...@...> wrote: > > Hi all, > > I picked up a new Yaesu FT-450 over Xmas and have discovered that the > transmit passband seems very uneven to me. Using the same settings, i.e. > audio drive, USB DATA mode, constant RF POWER selection - a single tone > from the soundcard at 500Hz could produce 20W, a tone at 1000Hz 7W, a > tone at 1500Hz produces only 3W output and at 2000Hz it is down to 1.8W. > > The interface is a Signalink SL-1+ and I know it works fine because I > have used this same interface (and soundcard) with an FT-897D for years > without problem. > > Has anyone else got an FT-450 on this group and could do a similar test > to see whether it is just my rig that has the problem or it is these > radios in general? The firmware in mine is 0194. > > Power out in CW mode is 100W without difficulty. > > I suppose using PSK31 the problem is not severe but wide bandwidth modes > like ALE or MT63 e.t.c., could be a real problem. > > Other than this the FT-450 seems a very nice little rig and at $616 from > AES was too good to resist. The RX is very nice but you need to play > with the DSP a bit to get the most out of it. Surprisingly (at least to > me) it is superb on AM SWL broadcast too. > > Thanks es 73, > > Sholto > KE7HPV >
