Simple micro transmitter

[Murphyv310]

Hi.
I have removed the AF preamp and substituted an old out put transformer wired to drive the modulator from a higher impedance.
This works a treat with little or no detectable distortion and good linearity on the scope.
I have done a range test and its here on Youtube. https://youtu.be/51d4TAEV1X0
Next thing is to find my matching TX that has disappeared and rebuild it in to a little case.

[pwdrive]

I watched that one too, I can see where you got your user name from.

Lawrence.

[Pat Pending]

Very impressive Trevor, (and I'm no fan of TV's generally but the 310 was arguably the most stylish set of its era)

Don't pump the range up too much though or the man from the home office will come calling 

Cheers.

[Murphyv310]

Thanks very much
I'd be surprised if it could reach across the road, the power is less than an AMT3000 micro tx, I think the tank circuit is helping TBH. I've heard from good authority that Medium wave interference is no longer investigated. Whether they'd ever want to know about a couple of micro watts I doubt.

[Mike Watterson]

Sadly you have to threaten legal action to even get serious RF interference investigated.
Otherwise they would have to ban ALL power line Ethernet and very many chargers, CFL ballasts, LED mains PSUs etc would fail.
Comments just today on the "outsource" of Tech government stuff to Ofcom.
http://forums.theregister.co.uk/forum/1/...alum_kerr/

[Murphyv310]

Bloomin typical.

[Mike Watterson]

Sadly

[Mark Hennessy]

Posts regarding testing crystals moved to a new thread: http://golbornevintageradio.co.uk/forum/...p?tid=6121

[Murphyv310]

Hi.
I've rebuilt the circuit into a small biscuit tin which of course is fully screened, I've also fitted a single holder for the AA battery and a clip for the PP3. It isn't quite complete as yet as I need to fit an aerial and earth socket and phono AF input, been waylaid with the Tandberg.............. Too many projects and not enough time

[Valvebloke]

... Too many projects and not enough time  

I know just what you mean Trevor ! I recall hearing that Lenin used to mutter "So much to do, so little time ..." every so often. Mind, his project was bigger than most of ours, I suspect, https://en.wikipedia.org/wiki/GOELRO_plan .

VB