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Messages - Thermionic

Pages: [1]
General Radio Discussion / Loran A
« on: July 10, 2020, 0033 UTC »
Does anyone have any WAV or MP3 audio files of Loran A as heard on top Band between  1,750 and 1,950 kc/s..

Utility / Trenton Volmet
« on: April 26, 2020, 0021 UTC »

Utility / Bankok Volmet
« on: April 26, 2020, 0015 UTC »
6670 USB via http://websdr.ewi.utwente.nl:8901

On air 10 and 40 mins

SDR - Software Defined Radio / Re: Kiwi SDRs
« on: March 14, 2020, 1010 UTC »
The Twente SDR is able to handle a large number of users at one time, I forget what the limit is, it could be 100 or more. KiwiSDRs are generally limited to 4 users due to the hardware. So if you camp out on one for hours at a time, you're preventing others from using it.

The fact that you have to ask why there are time limits is also the reason there are time limits.

Thank heaven for SDRs like Twente, NA5B and K3FEF et al, at least I can switch the computer off at night, go to bed and when I switch it on in the morning, I find I haven't timed out due to inactivity.

Please don't tell me you stay connected to an SDR overnight, while not actively using it.

The reason why I stay connected is because I have my browser set to restore previous session.

SDR - Software Defined Radio / Re: Kiwi SDRs
« on: March 13, 2020, 1048 UTC »
The fact that you have to ask why there are time limits is also the reason there are time limits.

Thank heaven for SDRs like Twente, NA5B and K3FEF et al, at least I can switch the computer off at night, go to bed and when I switch it on in the morning, I find I haven't timed out due to inactivity.

SDR - Software Defined Radio / Kiwi SDRs
« on: March 12, 2020, 2207 UTC »
Why is it these SDRs have time limits. Some cease to be active after so long.

Sorry, this KiwiSDR has an inactivity timeout after 30 minutes.
Reload the page to continue.

While there are others who cut out altogether and then this comes on the screen.

Sorry, this KiwiSDR can only be used for 30 minutes every 24 hours by each IP address.
Please check kiwisdr.com/public for more KiwiSDR receivers available world-wide.

If you have an exemption password from the KiwiSDR owner/admin
please enter it here:

I was listening to Shanwick radio on the emeraldSDR QRG 5598, On the waterfall I also saw Shanwick wkg flights on 5649. I duplicated the tab on browser, so I would be able to listen to 5598 and 5649 simultaneously.  When I clicked on the tab I saw this.

Multiple connections from the same ip address not allowed.
Client ip =

At least you don't get that sort of thing on the likes of Twente,  NA5B and K3FEF et al.


My first radio was by way of a Christmas present. I received it when I was 17, a few months after I'd joined my local radio club. The model a Pye 1101A.


As it was a table model, it lacked a BFO, which meant I couldn't resolve SSB or CW stations. This was solved by using a Class D wave meter.



I coupled the wave meter to the antenna lead which fed the RX and by using the second crystal which covered 1900 to 4000 Khz or 4000 to 8000 KHz I was able to zero beat the frequency and resolve the SSB.

One night I wondered if there was anyway I could modulate the 1mHz crystal. I got hold of a piece of two core wire and four crocodile clips, at one end I clipped the terminals of the loudspeaker of my record player, while at the other end I used one clip connected to the chassis of the wave meter, the other clip went to one of the pins of the crystal. Guess what, it worked. Every 1mHz I could hear what was coming from my record player. I unsoldered one of the leads from the amplifier to the speaker terminal and screwed it to one of the crocodile clips. From now on I used the Pye RX to listen to my records.

I had some copper wire which I used as my antenna which went from the shack (my bedroom) to one of the poles which held the washing line in the garden. I found I could hear my record player  when held a transistor radio in close proximity to the antenna.

Later I used the same method of using the 465kHz IF of an AM transistor radio. TRX1 connected to a record player or whatever tuned to 1600kHz while I listened to it on 1135kHz via TRX2. The range was limited to a few inches, but when I used the 10.7mHz IF of an FM transitor radio I found I could hear my record player more than a few yards away from the house.

I've had many radios since to numerous to mention. I had to give up my hobby when I moved into retirement accommodation due to QRM from the CCTV and the fire and security alarms, but thanks to WebSDR radio which I've only just found I can resume the hobby.

SDR - Software Defined Radio / Re: New To SDR
« on: March 12, 2020, 1030 UTC »
Welcome, on the STANAG, it's always been there, you just called it rtty. There was also its more redundant cousin, vft, if you remember that nice buzzsaw sound.

Now I never knew that. As I haven't done much SWL for quite sometime, when I found SDR, I thought what's happened to all the RTTY stations I used to hear, now I know.

SDR - Software Defined Radio / New To SDR
« on: March 11, 2020, 1535 UTC »
I only discovered WebSDR a couple of days before last Christmas. What brought it to my attention was when I was looking for the sounds and interval signals I used to hear when I was much more active in SWL than I have been lately. I clicked on a link, which turned out to be the Twente WebSDR. I thought what the hell is all this, it didn't take me long to find out what I was looking at.

I've been on the Internet since 2004. I see the Twente SDR came on line in 2008 and was reactivated in July 2012 after an interruption of more than 1.5 years. I can't believe it's taken me until now to discover not only Twente, but other SDRs.

What I first noticed about shortwave radio is how much it has changed since I last listened to it nearly 30 years ago. In my days of SWL there were was no such thing as STANAG, now it's all over the place.  Then there's the waterfall, this was something new to me. I must tell you when I went to bed on the night when I found Twente, all I ever dreamed about was that waterfall.

The second SDR I found was NA5B, which as most of you know is in Washington DC. Back in the days when I used to listen I had a brief flirtation with medium wave DXing and found the odd America and Canadian station on that band. Thanks to NA5B I now have the ability to listen to American AM stations on Medium Wave.   

As there are no broadcasting stations on the long wave band in the North American countries, being a resident of the UK I've often wondered what it sounds like from across the Atlantic. The only station I've heard is Radio Algeria on 252kHz. It's weak, but you can detect audio from it. Moving to 198kHZ which is used by BBC Radio 4, there is a line on the waterfall and a very, very weak carrier wave. One night I could just detect some barely perceptible audio.

It was through the Twente SDR that I found this forum through a link someone had posted in the chatbox.

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