Just got a couple of RTL-SDR V3's the other day. Having the TCXO dramatically improves the frequency accuracy compared to the cheap DVB-T dongles. VK3RXX saved for future reference. Thanks
That little antenna was impressive. The fact that turning it made such a difference to reception. I wonder how a downconverter would go at bringing it down to the to range of a Baofeng. Or a cheap UHF CB handheld, using a nanovna as the oscillator. I've been playing around with downconverting. I have downconverted a signal on 487.600mhz, which is the output of the repeater of a local taxi company, to the UHF CB band. Results have been excellent, and the frequency is quite active. I originally used my nanovna as the oscillator, and due to the oscillator frequency required, just 10 to 11mhz range. I had a go at building my own. This was the first crystal oscillator I've built. I had an old 27mhz CB I picked up that had a heap of crystals. Two matched up with what I needed. The end result is a downconverter using just seven components. The crystal oscillator circuit I got off TH-cam. I'd had the circuit for some time. It was described as a crystal tester. With the crystal it's just six components. 2 capacitors, 2 resistors, a general purpose transistor and the crystal. I don't think it's a colpitt's. It worked first go with several crystals I had at hand. From 10mhz to 20 something. It worked from 9 volt, and all the way down to 1.2 volt. A double A rechargeable. The mixer is a single germanium diode. Output from the oscillator goes to one end of the diode. Alligator clip lead goes to this end for the antenna. Alligator clip lead to the other end for the the output. The CB handheld only needs to be near the output. The squelch is triggered with no problem. Using a 10.625 crystal. The difference with bring the 487.600 frequency down to 476.975. This is channel 23 on the UHF CB band. My other suitable crystal will place it on channel 24.
Found the round loop type a bit easier to construct, nice confirmation of the usefulness of the Quansheng outside its intended range even with modifications. Thanks Peter
The Quansheng UV-K5 is probably an FM so the steady freq of cw is probably seen as noise with no deviation. so other than change of hiss probably no idea of signal. maybe use sdr to receive the handies IF.
The UV-K5 uses the 430 Mhz LPF that kills the RX and TX, if you bypass the filter you get full RX sensitivity better than the rtlsdr and 5 mw of output power
Quansheng requires a change to the first transistor in the receiver circuit and a change to the filter, otherwise it doesn't work on 1296MHz. Work in progress, (very slowly).
Just an observation, but why do you quickly cut to slides for like 2 seconds? Not many people are quick enough to be able to see properly what it is you're cutting to unless they pause the video which isn't always convenient.
This Is A Super Good Video, But I Would Do Some CRAZY Things To See How To Make Proper PMR 446 Band Antenna, I Can`t Figure It Out, Om Papers I have Built Numerous 446 ANtennas, But Non Of Them Can Receive 1000M Away So Thats SAD! Sometimes It Picks Up Some Car Driving Classes Students With Bikes Where They Use PMR, But Other Then That, I See Only Spikes And Spikes Are To Narrow To Hold Any NFM Information, Any Help?
The black art of microwave 😝😝. I’m busy destroying QRP LABS progrocks…. 2 dead 1 to go 😝😝😝. How do you find the Quangsheng on 70cm and 2m? Loved this video 73.
this shows why amateur constructions make sense, as attempts to outperform the industrial built, which is nice. i mean if a hobbist believes he can make better that industrial, at least sometimes, it may not be foolish. this video is good news for amateur
Just got a couple of RTL-SDR V3's the other day. Having the TCXO dramatically improves the frequency accuracy compared to the cheap DVB-T dongles. VK3RXX saved for future reference. Thanks
Always informative as per usual Peter. I will look into purchasing an SDR.
That little antenna was impressive. The fact that turning it made such a difference to reception. I wonder how a downconverter would go at bringing it down to the to range of a Baofeng. Or a cheap UHF CB handheld, using a nanovna as the oscillator. I've been playing around with downconverting. I have downconverted a signal on 487.600mhz, which is the output of the repeater of a local taxi company, to the UHF CB band. Results have been excellent, and the frequency is quite active. I originally used my nanovna as the oscillator, and due to the oscillator frequency required, just 10 to 11mhz range. I had a go at building my own. This was the first crystal oscillator I've built. I had an old 27mhz CB I picked up that had a heap of crystals. Two matched up with what I needed. The end result is a downconverter using just seven components. The crystal oscillator circuit I got off TH-cam. I'd had the circuit for some time. It was described as a crystal tester. With the crystal it's just six components. 2 capacitors, 2 resistors, a general purpose transistor and the crystal. I don't think it's a colpitt's.
It worked first go with several crystals I had at hand. From 10mhz to 20 something. It worked from 9 volt, and all the way down to 1.2 volt. A double A rechargeable. The mixer is a single germanium diode. Output from the oscillator goes to one end of the diode. Alligator clip lead goes to this end for the antenna. Alligator clip lead to the other end for the the output. The CB handheld only needs to be near the output. The squelch is triggered with no problem. Using a 10.625 crystal. The difference with bring the 487.600 frequency down to 476.975. This is channel 23 on the UHF CB band. My other suitable crystal will place it on channel 24.
Excellent idea!
Thanks for sharing your experimental approach and results.
Lovely! 👍
How can we build this downconverter? Link please?
@@PureAwareness76 This doesn't have the circuit, but demonstrates it.
th-cam.com/users/shortsC2hrZXTatFg?si=ssZyejo0ltAdSzsU
👍Thanks for video Peter. I liked the homebrew antenna. Impressive performance for a small piece of copper wire.
Found the round loop type a bit easier to construct, nice confirmation of the usefulness of the Quansheng outside its intended range even with modifications. Thanks Peter
This will be a good test
RTL will easily win.
I measured approx -74dBm sensitivity for my UV-K5 on 1297MHz and RTL is much more sensitive there.
How about vs quangsheng with V2.1 SI4732 chip full HF band mod? Have you tested this?
With the Quansheng someone has made a small PCB to improve HF operation. It would be amazing if a 23cm modification could be made for the Quansheng.
The Quansheng UV-K5 is probably an FM so the steady freq of cw is probably seen as noise with no deviation. so other than change of hiss probably no idea of signal. maybe use sdr to receive the handies IF.
ahh the "bowtie", used to use those for stretching wifi links back when it was enthusiast gear and not easily available
What was the difference with and without the reflector? I have been amazed at the way 1296 will bounce off buildings and even passing planes.
Only a few dB - but still worthwhile
Ha ha …. The dog did a cameo like in your toy CW video…. I was just watching it !
The UV-K5 uses the 430 Mhz LPF that kills the RX and TX, if you bypass the filter you get full RX sensitivity better than the rtlsdr and 5 mw of output power
Quansheng requires a change to the first transistor in the receiver circuit and a change to the filter, otherwise it doesn't work on 1296MHz. Work in progress, (very slowly).
Thanks 👍
Hard to carry out this test in the UK as there is nothing to hear on 23 cm.
Nice work! Always been interested in microwaves. No one around here cares 😒
Just an observation, but why do you quickly cut to slides for like 2 seconds? Not many people are quick enough to be able to see properly what it is you're cutting to unless they pause the video which isn't always convenient.
This Is A Super Good Video, But I Would Do Some CRAZY Things To See How To Make Proper PMR 446 Band Antenna, I Can`t Figure It Out, Om Papers I have Built Numerous 446 ANtennas, But Non Of Them Can Receive 1000M Away So Thats SAD! Sometimes It Picks Up Some Car Driving Classes Students With Bikes Where They Use PMR, But Other Then That, I See Only Spikes And Spikes Are To Narrow To Hold Any NFM Information, Any Help?
The black art of microwave 😝😝. I’m busy destroying QRP LABS progrocks…. 2 dead 1 to go 😝😝😝. How do you find the Quangsheng on 70cm and 2m? Loved this video 73.
Quansheng seems to be pretty good on 2 & 70. Mainly used it on DSB.
@@vk3ye Thanks Peter! 73
this shows why amateur constructions make sense, as attempts to outperform the industrial built, which is nice.
i mean if a hobbist believes he can make better that industrial, at least sometimes, it may not be foolish.
this video is good news for amateur
Проверил свой кваншенг и он тупой на 1296мгц. Плохо слышит генератор на 1296мгц. Всего пару метров с нановна.