Valve MF pantry transmitter.

[G6Tanuki]

I got bored... And built a MF pantry transmitter using an ECL80.

The triode is an xtal oscillator which feeds the output stage which is screen modulated using a backwards connected transistor radio 'LT44' driver transformer to connect to the high impedance headphones output of the ancient Nokia phone I use for streaming.

Feeding audio to my Roberts R707 it sounds rather good. Currently listening to a bunch of Dusty Springfield tracks through ithough.... The R707 has some serious punch and really handles Dusty's wide open vocal style well.

Play loud and forget about the neighbours!!

[Electronpusher0]

Sounds good, any chance of posting the schematic?

Peter

[G6Tanuki]

Originally Posted by Electronpusher0

Sounds good, any chance of posting the schematic?

Peter

Sure - Ii'll post a schematic and suggested component-values [hand-drawn, I no longer have an Autocad license] in a couple of days.

It really does seem to work well, it's great to be hearing Dusty's wonderfullyfully full-on vocals resonating round the summerhouse.

[Historic sidenote: I'm using a 1.333MHz carrier crystal that first did duty as the clock-oscillator in a 1970s |D|I|G|I|T|A|L| PDP8E.]

[paulsherwin]

The usual caution applies: you should watch the range, depending on your domestic circumstances. Even a weedy ECL80 can chuck out quite a bit of power with a half decent aerial.

[Electronpusher0]

Thanks Paul, noted. I certainly do not want to go outside the boundary of the house.
Peter

[G6Tanuki]

For reference, the 'output' part if my ECL80 panty-transmiter consumes 10mA at 220V.

It's not in in any way coupled to any of my 1.8/3.5/5.5MHz "cloudwarmer "NVIS ham-radio antennas.

Though part of me wonders just if there's anys sort of "DXCC" certrificate for MW pantry-transmitters or their Band-II FM equivalents.

[turretslug]

Reception report from OFCOM?