Crystal sets, POW radios, spy sets & radio related thread

I'm using one of these at the moment hanging off the fridge door ;-)

You just need a cheap rotator now and put it in the loft.
I noticed that SDRPlay have updated their firmware to be compatible with some software that allows remote control and access over the LAN. It also allows for both receivers of the Duo which other 3rd party software doesn't. Handy for monitoring HF and VHF or just different stuff in general.
 

endure

GCM
Here's SDRUno

sdruno.jpg
 
Technology has moved on in leaps and bounds since this time ... my Marconi CR100 in the 1950's ... which I mentioned earlier in this thread but have now found a photograph ... antennae was a long wire achieved by my throwing a Tennis Ball over the house roof and pulling a wire across ... I later installed the "S " Meter within the case . I think I paid ~£5 for the CR100 and sold after much enjoyment / enhancement for a profit .

CR100 WL.jpg


.... note the mug of tea ... even as a schoolboy must get priorities right .
 
Here's a pic of my SDRPlay running SDR Console V3 (free) listening to China Radio International tonight. The programme was teaching a German Bloke Mandarin ;-)

SDRPlay do their own (also free) software to go with the hardware but it's overkill if you just want to listen to PRC propaganda...

View attachment 501707
I can't make out the ranges on your X or Y axes, but why do you have signal strength roll-off at the edges? Do you maybe have a tunable antenna?
 

endure

GCM
I can't make out the ranges on your X or Y axes, but why do you have signal strength roll-off at the edges? Do you maybe have a tunable antenna?

That's the way the SDR software works. You just shuffle up (or down) the band a little and it opens up that part of the band.
 
I can't make out the ranges on your X or Y axes, but why do you have signal strength roll-off at the edges? Do you maybe have a tunable antenna?
A high Q tunable loop would tend to have a much steeper curve and a fairly narrow bandwidth. Much steeper than to account for all those signals. Such loops need to be retuned whenever you change frequency unless there is some form of autotuning.

The barn door front end of the SDR receiver allows simultaneous display of a very wide range of frequencies, something like 2MHz. That is the fall off you see at either end. The software selectable bandwidth, for the signal you want to tune in to, can be varied to a tiny subset (e.g 200Hz, 2.4KHz, 9KHz) of the 2MHz (or whatever) selection, say just like a variable passband filter.

Have a look at SDRs on sdr.org to get a closer look at this. You will soon get the idea.
 
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Anyone have any recommendations for amateur radio software that can be used with most common transcievers for data modes and display?
 
A high Q tunable ....

One of the mods I carried out on my CR100 was to make and install in the IF circuitry a " Q Multiplier "... made around a Litz wire wound coil to enable variable selectivity and increasing gain when QRM was bad ... I suppose the joy then was that there was so much space inside the kit and with mainly valve technology it was possible to very personalise , at small cost , and vastly improve the performance of a surplus Communications Receiver .
 

endure

GCM
I can't make out the ranges on your X or Y axes, but why do you have signal strength roll-off at the edges? Do you maybe have a tunable antenna?


That picture shows 2Mhz of the band. The spikes are individual stations transmitting. To tune to one you just use your mouse to move the cursor to it.

You can have a play with SDR radios online at websdr.org

E2A Here's a bloke that explains how it works


 
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Gents, I appear to be at "beard Max" - soldering iron is out- think a bit of beard residue still left over from yesterday. Today - I'm gonna use the 200 in 1 projects electronic kit and make a morse code generator thing, and knock up a crystal radio to receive the signals. Not sure this is going to work or not. I've gathered a few links and YouTubes and going to attempt various things, incorporating various components that are on the electroninc kit board.

2020-09-04 13.07.28.jpg


I'm soldering metal connectors onto my piezo earpieces...and will cast an 'educated eye' around the room towards anything else that might do better from a bit of soldering...there's a Thomas the tank engine toy with a loose battery connection. I love my Thomas the tank engine toy...
 
I stumbled upon this Norwegian chaps You Tube Channel. He likes to keep the equipment in working order and uses them for field tests. Subtitles on the videos.



Other videos at

Helge Fykse

I could still read some of the Morse .... but for certain not all !
 
Can anyone identify the radio in this? It's my grandad. He died in 1980 - I never really knew him. He was into his shortwave radio stuff though and had notebooks with callsigns etc.

I'd quite like to get one.
Edit..top of chair around centre you can just make out a wire. Other phots show he had it in a dipole arrangment on that wall.
family photos2.jpg


He didn't even need a beard because ...he smoked a pipe!
 
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Can anyone identify the radio in this? It's my grandad. He died in 1980 - I never really knew him. He was into his shortwave radio stuff though and had notebooks with callsigns etc.

I'd quite like to get one.
Edit..top of chair around centre you can just make out a wire. Other phots show he had it in a dipole arrangment on that wall.View attachment 501930

He didn't even need a beard because ...he smoked a pipe!

Is that you on the bottom left?

I imaginmed you as taller somehow.
 
Some Norgi accented characters in there...
TBH it was mainly Call Sign info and some of the procedural characters . .
 
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