Re: [gqrx] Digest for gqrx@googlegroups.com - 1 update in 1 topic
Dennis Eckert
At night, with the converter engaged with the right frequency offset set in the software for whatever converter you are using, you should be able to hear WWV shortwave time station on 2.5, 5.0 and maybe 10.0 mHz. You most likely will need a different antenna plugged into the converter-- find some wire perhaps 1015 or 20 feet long, strip one and of the insulation, and plug the bear and into the antenna port on the converter . Put put the wire outside like through a window and stretch it out. And then listen again.
When you use an SDR program with the Ham It Up converter AND have the proper frequency offset set in the software ( which I think should be minus 125.00 mHz) then you should use the software tuning for any frequency below 30 MHz as displayed in the software. It seems like you are hearing VHF National Weather Service transmitter in the software at 57 MHz, which may be some kind of image frequency. radioreference.com for your county in Pennsylvania show that the two VHF weather transmitters closest to you in Pittsburgh and Johnstown are in the middle of approximately 162 MHz.
You said --". I also tried tuning around the aircraft bands with the box engaged and no signals on shortwave, what am I doing wrong?" When you asked that question, it is unclear to me what you mean about the box engaged? If that means you have the converter engaged in the software with the proper minus frequency offset for that converter, that would explain the misunderstanding. With the converter engaged with the proper frequency offset , I am explaining in a different way than I did as above but with the same point – – do you hear HF signals within converter on, you would type in the actual age HF frequency . In other words, you should not be tuning around the VHF aircraft frequency band with the converter turned on and the proper offset set in the software.-- OK?
I see by your ham radio profile in qrz.com that you have a Tecsun HF portable receiver. Takes me back to my gradeschool days in WMBI Chicagoland of hearing HCJB, Quito Ecuador in 1957-1958w. So I assume you have familiarity with the HF broadcast bands known as 31 meters19 m etc. That means with the HF converter turned on and the proper frequency offset , tune in your Tecsun to the strongest HF signal you hear on your best band day or night. And then go to the SDR dongle with the software and tune to the same frequency and compare the signal strength between the two receivers.
What I am about to say next may not have been covered in your ham radio technician license class exam – – when you decrease the band with of the receiver , you will be able to hear weaker signals then with the SDR set at maybe 2 MHz of bandwidth. I am a Morse code CW guide – – that means for the best sensitivity of the SDR dongle's on the 20 m CW band, I set the bandwidth with parameters for approximately 100 kHz-- 14.0 to 14.10. And it makes a significant difference. Try this – – W1AW 20 meter daily transmissions are on CW frequency of 14047.5 kilohertz. Check their daily schedule at ARRL website. When you hear them on the SDR receiver, keep narrowing the bandwith with the software and notice how stronger they become as you continue to narrow the bandwidth on the SDR receiver. Pretty remarkable, right?
It used to be very expensive for ham radio transceivers to have a spectrum display like GQRX, which is great for DX operators who can now see on the spectrum display the strongest and weakest signals. Before this panadapter and SDR technology, we had to keep our hand on the tuning dial to find strong frequencies, right? I am a QRP CW guy with an Elecraft K3 XCVR. My narrowest CW filter is 400 hertz wide -- again, that is 400 cycles per second. In crowded band conditions, with interfering stations and noise, I can use the DSP technology in the Elecraft to narrow that 400 Hertz bandwidth to around 30 to 50 Hertz!
Likewise for your HF listening, look at the international HF allocations and narrow the bandwidth to cover just that particular band and however many hundreds of kilohertz it is wide.
I had meant to send this to you via private mail but then I thought it would be of help to the group to let them know I was trying to help you on issues other then specifically GQRX.
Dennis KB7ST central Washington state
On April 1, 2017, at 5:10 PM, gq...@googlegroups.com wrote:
- what in the world? - 1 Update
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James Clark - KC3CDV <james.c...@gmail.com>: Apr 01 01:21PM -0400
Hey guys, I got the ham it up running and it seems to be working, but its weird, I am hearing VHF weather on 57MHZ, thats strange within itself. I also tried tuning around the aircraft bands with the box engaged and no signals on shortwave, what am I doing wrong? I am going to keep tinkering, but for now I am off to read my bible, thanks for the help you can give in advanced. I lowered the conversion stage on GQRX, I engaged the box, the only thing Ive not tried is the samplerate. May Peace Be With You. Active skywarn severe weather spotter and Community Collaborative Rain, Hail & Snow Network operative. @HomefrontHugs Volunteer for our Troops and Families |
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Simon Kennedy
James Clark - KC3CDV
I don’t know if I am at 0 or not, I guess i’ll just go back to my saved settings as at the time I did not play with that sort of stuff at all.
I am not even sure how to set the offset on GQRX, theres a few different sliders but voiceover just says increasing or decreasing, it won’t tell me the actual value.
Yeah Ive played with the filters quite incredible, Yeah I had a tecsun at one point and that was a nice little radio and I know the AM broadcast on shortwave quite well, and those freqs are quite wide and I cant hear a thing.
The only freq limit I can tune is the hardware freq, I cant use the waterfall and I think thats where the software limit is rite?
OK so i’ll tune to a strong FM station and then make sure the desplay reads the correct freq, I can do that then I guess I go to what 24Mhz with the ham it up turned on and then go and see if I hear shortwave?
When I meant the box was engaged buy the way I meant that the ham it up was bypassing all the freqs and such and trying to do its job.
Thanks for all the help thus far.
May Peace Be With You. Active skywarn severe weather spotter and Community Collaborative Rain, Hail & Snow Network operative.
@HomefrontHugs Volunteer for our Troops and Families
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