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# Any 433/315MHz receiver hacker around ?

#### Externet

Aug 24, 2009
869
Hi.
Those cheap general purpose modules meant to receive 433MHz signals... how to make them work at ~140 MHz, or 150 MHz, or 100 to 200 MHz ? I assume other inductors/capacitors should work shifting tuning, if the chip is capable...
Know any links to someone doing it ? How would you do it ? Receiver only, not interested in transmitter.
Where to find schematics/data sheets for those ?

#### davenn

Moderator
Sep 5, 2009
14,150
how to make them work at ~140 MHz, or 150 MHz, or 100 to 200 MHz ?

It would be a significant alteration. Easier just to build an appropriate freq. circuit
what are you actually trying to achieve ?

#### 73's de Edd

Aug 21, 2015
3,477
Sir externet . . . . .

That's also what I am wondering . . . . . is what that you are up to ?, considering that the crux of the units that you gave referencing to were being 433 mhz units.
Your viaible other units would be falling in the US allocated freq slots below:

Of those units seen, the receivers were being of superregenerative design, and the transmitters were being the one critically spec'd units with their required frequency accuracy and stability being achieved via SWIF filter technology.

Will the desired receiver aspect of yours be needing just transmitter carrier detectuion presence, or processing additional tone or digital pulse stream info ?

Le Schematiques . . . . .
https://tinyurl.com/udatytu

73's de Edd . . . . .

A flying saucer is the result of a nudist spilling his HOT coffee in his lap.

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#### Externet

Aug 24, 2009
869
Thanks, Edd.
Yes. Products capable of much wider performance than the data sheet or applications mention. Because nobody thinks/is after the 'unusual uses' should not forbid from new applications, ISM or not.
If my operation license allows me to do it in another band, why do I have to hit a brick wall on the data sheet ?
There is several chip architectures for receiving 315/433 MHz. Perhaps one or the other can work just fine. Yes, anyone you know using these chips/modules tweaked for 144MHz ?
Yes, carrier presence detection; OOK.

Your link shows me nothing extraordinary in its schematic as to prevent other (nearby) frequencies from performing.

Are we left to guess-try-and-learn ?

#### Externet

Aug 24, 2009
869
what are you actually trying to achieve ?

Hi. Exactly to substitute ~$200 VHF receivers with these$2 chinese toys when the performance needs are forgiving enough.
That is why the data sheets of those types of Rx ICs (not the modules !) should help discern limitations.

#### davenn

Moderator
Sep 5, 2009
14,150
That is why the data sheets of those types of Rx ICs (not the modules !) should help discern limitations.

I think you will find that the limitations ( freq range) are in the chip

#### Externet

Aug 24, 2009
869
OK. Ordered Rx modules apparently with a similar to these schematics; as a guess of hack-friendly. Will scratch my head until arrive, and if you see something to suggest, welcome.

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