Hi Merle,
W0EWM wrote:
>I would be interested in knowing what the problem is that is being
"researched?" I ran a bandwidth test, using the spectrum facility in
Hamscope and I can clearly see the bandwidth (Displayed as an amplitude
peak) of the 250Hz filter. I can also see the 500Hz, the 1KHz, the 1,8KHz
and the 2.4Khz. The 6KHz and the 20KHz are wider then the spectrum display
in Hamscope. So I'm not sure what Mark discovered? And Bill, I'm not sure
what the 250Hz filter problem is that is being worked on. Do you know more
about the problem? My test indicates the 250Hz filter is working as
expected?
I assume you are using 1.371. I'm using a beta version of 1.372
which has a very similar issue, but I don't plan to reload 1.371 just
to verify what Mark says. Ten-Tec apparently has been investigating
different alternatives with the 500/250 filter scheme and the control
firmware was not restored on the 1.372 beta sent out. From Mark's
comments, I surmised 1.371 may have gone out with the same issue, but
I have not personally verified this. If you are using 1.371 and don't
have the problem, Mark must be experiencing a different problem, but
his sounded similar to what I see in the 1.372 beta.
I check my filters using a wideband RF noise source and Spectrogram
v5.17 to view the audio output of the filter passbands. You can also
do this by using a signal source plus Orion's internal 6 dB attenuator
and S-meter to check the 6 dB points of the filters. The only important
point to remember is to always set DSP = 6000 (as Mark did) in order to
remove any DSP filter effects when checking the roofing filter BW. Of
course you must also have the appropriate filters enabled in the Filter
Menu. By the way Mark, did you enable your 250 Hz filter? Perhaps that
was causing the problem you are having.
73, Bill W4ZV
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|