Public SDR tuning a radio

[Big Kahuna]

Had someone tell me recently that their radio was off frequency on LSB and they didn’t have a freq counter or test equipment so they tuned to a local SDR and made adjustments in the radio until they sounded on frequency there.

Interesting way to do it but makes me wonder, are public SDR like Kiwi SDR a good reference and how do you know they are calibrated and on frequency? I’m guessing most of them are probably more accurate than many CB for frequency stability.

 

[Pete Fender]

Every serious radio user, CB or Amateur, should have a frequency counter.
I have a Dost TFC-3001, with Watts, SWR, modulation, and frequency counter.
Usually, the person telling me I am off frequency is the one off frequency.

 

[Big Kahuna]

Every serious radio user, CB or Amateur, should have a frequency counter.
I have a Dost TFC-3001, with Watts, SWR, modulation, and frequency counter.
Usually, the person telling me I am off frequency is the one off frequency.

Agreed that was one of the first tools I ever purchased and I always encourage others to buy one - but as mentioned in many areas there are often 2-3 people telling each other that they are the one off frequency. Makes the Public SDR an interesting tool possibly to settle the argument But again that brings up my question of accuracy on the SDR.

 

[Handy Andy]

Interesting...

When it comes to being "off" several hertz or kilohertz, the measurement is thru the listeners ear...

Every time...

You can be "on frequency" per your own frequency counter - and even heterodyned with it's own 10MHz Xtal with WWV time signals for showing such a reference...

You still have someone that can sound a little "off"

So the SDR can be used as that reference tool to make the listener "hear" themselves compared to others (3rd part or observer reference) a relative reference to the tuning or being on frequency. Simply by using the SDR to tune to the other listener - spot on, then tune your radio to what the SDRs' "spot on" - and wham - everyone's happy again.

Goes back to the "Monitor" radio for SSB tuning - once everyone's tuned to the "Monitor Radio's" frequency, everyone will or should sound the same - for it's the reference - even if it's several hundred hertz off - everyone can tune the same direction and wind up being in exact spot on sound the same - even though they are still not on the reference frequency they started out on.

So the concept is not unique, but it's the references to using an SDR to re-tune the radio. So the listener and the radio (other operators) in question - can then "sound the same" even though they may now be off to "center" they don't care for it's the listeners ear that's satisfied.

 

[Big Kahuna]

Interesting...

When it comes to being "off" several hertz or kilohertz, the measurement is thru the listeners ear...

Every time...

You can be "on frequency" per your own frequency counter - and even heterodyned with it's own 10MHz Xtal with WWV time signals for showing such a reference...

You still have someone that can sound a little "off"

So the SDR can be used as that reference tool to make the listener "hear" themselves compared to others (3rd part or observer reference) a relative reference to the tuning or being on frequency. Simply by using the SDR to tune to the other listener - spot on, then tune your radio to what the SDRs' "spot on" - and wham - everyone's happy again.

Goes back to the "Monitor" radio for SSB tuning - once everyone's tuned to the "Monitor Radio's" frequency, everyone will or should sound the same - for it's the reference - even if it's several hundred hertz off - everyone can tune the same direction and wind up being in exact spot on sound the same - even though they are still not on the reference frequency they started out on.

So the concept is not unique, but it's the references to using an SDR to re-tune the radio. So the listener and the radio (other operators) in question - can then "sound the same" even though they may now be off to "center" they don't care for it's the listeners ear that's satisfied.

Yeah I guess if three people all key up and 2 of them sound normal on the SDR and the third on sounds off they could tell the third guy, nope go online and list to both of us and you're the one that's off.

This of course only fixes the TX frequency - if someone has RX and TX tied together but their radio is misaligned they could potentially still have a problem, but if all three are then TXing on the same frequency it could solve that age old argument of who is the one who is off frequency.

Still makes we wonder if the SDR receivers are ever off frequency themselves. I know the two in my area both seem spot on but you never know.

 

[Handy Andy]

Still makes we wonder if the SDR receivers are ever off frequency themselves. I know the two in my area both seem spot on but you never know.

And you'd be correct...

If one or both - their own time-bases (their Xtals used to make their system run as well as their reference) are off, you wouldn't know unless you use another third reference and then it's a matter of which one to trust to fix the other two.

 

[guitar_199]

Confucious says.... "man with one watch... knows what time it is!"

If one or both - their own time-bases (their Xtals used to make their system run as well as their reference) are off, you wouldn't know unless you use another third reference .....

 

[Handy Andy]

Confuzion sez...​

​

Man with broken watch has more accurate dial TWICE A DAY than man with watch that is 99.999% seconds per day accuracy...

 

[groundwire]

Kinda off subject but i hate when guys say you're off frequency when its not exactly spot on. There was a smart man along time ago who invented the RIT function/clarifier for a reason.

 

[Big Kahuna]

Kinda off subject but i hate when guys say you're off frequency when its not exactly spot on. There was a smart man along time ago who invented the RIT function/clarifier for a reason.

Yeah I think in a two person conversation it's not really an issue but I think this comes up a lot when a group of 3 or more people are talking and if one person is off everyone else isn't going to adjust to them they're more likely to say "hey you're off".

I think the Public SDR is a great tool for people to hear themselves and others to compare freq, audio, etc. Never thought of trying to adjust a radio freq using it though, just an interesting idea.

 

[groundwire]

Yeah I think in a two person conversation it's not really an issue but I think this comes up a lot when a group of 3 or more people are talking and if one person is off everyone else isn't going to adjust to them they're more likely to say "hey you're off".

I think the Public SDR is a great tool for people to hear themselves and others to compare freq, audio, etc. Never thought of trying to adjust a radio freq using it though, just an interesting idea.

Thats true, in a round table conversation it can be difficult

 

[Slowmover]

Thats true, in a round table conversation it can be difficult

Why Jay in the Mojave post about one old bird setting the others to squawking about off freq is so funny.