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31st July 2011 16:56
Scott R,
LOL, sure why not?
Regards,
Alan
28th July 2011 07:29
Hey I think I heard you back then. Can I get a QSL card?
26th August 2009 21:14
Stuart,
The VCO would not be sufficiently stable to operate on 2 metres, at least not without a PLL.
You might be able to get an old VHF commercial radio you can reprogram for 2 metres. They often come up at junk rallies for very reasonable prices.
Otherwise as it is a fixed-frequency you could build an crystal locked TX for the frequency in question. You'd need to multiply up from a lower frequency to get reasonable deviation. DSE used to sell a kit with about 1 Watt out that did just that, more output would not be too difficult to arrange.
Regards,
Alan
9th August 2009 16:29
I too... like the look of this little VCO. How easily could it be teased into reliable service on 2m FM?
In particular, I'm looking around at a transmitter with about 5W output, to use for broadcasting the WIA National News on the VK4RBN (Mt. Glorious) Brisbane Repeater... transmitting at 146.4MHz for about 30 minutes or so. Limited income unfortunately means I cannot afford a 2m radio, and my TH-F7E handheld (sole 2m/70cm rig... the other rig is HF) will not transmit 5W for the period required.
8th June 2008 00:53
But I pushed 40mA,12V over a 2N2219!
And, what a pretty, small,hand-held VFO! Can I take a look at the schematic?
6th June 2008 18:50
Bert,
No, you don't!
It was a horrible beast, especially the amplifier. The output device was a 2N4427 with a clip-on heatsink. It was driven with two tuned stages which is probably why it had a tendency to take-off at the wrong frequency now and then. The oscillator was your average common-base thing, like you'd see in an FM toy microphone, feeding a simple and completely inadequate class A buffer with a tuned collector. The exciter stages were series tuned monsters with T-network matching (actually fairly good), delivering about 100 mW to that 2N4427 (probably one of the reasons I cooked a few).
Regards,
Alan
4th June 2008 20:46
Haha, you blew the transistors once a week, almost often as me. Every 24 hours, I have to replace my transistor with a new one!
4th June 2008 20:36
I want the schematic!
14th April 2012 19:41
Adam Eve wrote...