Re: [dxatlas] Skimmer on VHF/UHF
- g0dja wrote:
> I'm more into VHF and UHF than HF, so I have a reasonable set up forI don't know why I wrote 50km, it's actually 217km away. I think I was
> 23cm that is capable of hearing a CW beacon with the callsign GB3MHL
> about 50km away from me.
thinking of the much closer one at Emley Moor (GB3MLE) which is about
47km and is a collosal signal here of course. In fact, the Skimmer does
stuggle with that one, but there's a well known fault with the PSU on
the beacon which makes the CW note very rough.
Anyway, decoding on GB3MHL is much better today, so conditions may be a
bit better and the Skimmer can now decode about 99% of the time.
- Hi Dave,
The bandwidth of the input signal in the 3-kHz mode must be 3 kHz. If it is
less than that, the sensitivity of the decoder drops significantly. Your
signal has only about 1500 Hz BW - at this bandwidth, CW Skimmer can decode
only very strong signals. Please see if you can use a wider filter in your
73 Alex VE3NEA
> Alex, VE3NEA wrote:
>> Hi Dave,
>> Please send me a short I/Q recording of the 23 cm signal.
>> 73 Alex VE3NEA
> Hi Alex,
> The Skimmer seems to be getting the callsign and locator 99% of the time
> now, but I've attached a sample for you anyway.
> It got the call OK the second time, but thought the call was TI3MHL and
> occasionally gets the 3 as a 4.
> Cheers - Dave (G0DJA)
- Alex, VE3NEA wrote:
> Hi Dave,Thanks for the explanation Alex,
> The bandwidth of the input signal in the 3-kHz mode must be 3 kHz. If it is
> less than that, the sensitivity of the decoder drops significantly. Your
> signal has only about 1500 Hz BW - at this bandwidth, CW Skimmer can decode
> only very strong signals. Please see if you can use a wider filter in your
> 73 Alex VE3NEA
I guess that's because I was using the 'CW' setting on my TS2000X, the
width setting was 2000Hz.
I will try again using USB, as that allows me to go up to 50000Hz.
Although your point about needing a stronger signal is born out by the
fact that the stronger signal from the beacon today was being decoded.
I've been using the SDR-IQ on 20M with CWSkimmer today, and have got the
aggregator running now. However, I have noticed some errors coming up
on the aggregator DOS window.
One says "error:cannot send spot - http://skimmer.dxwatch.com/rx.php -
500 server closed connection without sending any data back" and the
other says "500 cant connect to skimmer.dxwatch.com:80 (connect: Unknown
error)" then the next time it goes through OK for quite a long time
until the next error message comes up.
I thought I'd mention these errors in case they mean something to the
operation of the aggregator.
Cheers - Dave (G0DJA)
- David Ackrill wrote:
> I will try again using USB, as that allows me to go up to 50000Hz.Ooops, that's a typo of course. The maximum width, with the TS2000X in
USB, is 5000Hz.
- Thinking ahead a little...
Is there a way to use the SDR-IQ/14 as a transverter IF, but have the
Skimmer log the spots on a different frequency?
For instance, in Europe the 4M band (70MHz) is becoming available in
more countries to Amateurs but many/most commercial radios don't cover
the band. Or, even if they do the resultant signals and receivers are
poor. Therefore, many people use a transverter for that band.
Similarly, on the higher microwave bands it's not uncommon to use
transverters from bands such as 10m/2m or even 70cm.