3rd July 2011 21:18
Bert,
It is not extremely sensitive, but for most signals on HF shortwave bands it is fine. It doesn't take too many components really, only a handful of transistors and passives.
Regards,
Alan
20th May 2011 00:27
Hi Alan,
This is quite an interesting and attractive receiver with an output for frequency counter. I am so tempted to build one too, but I can't waste my very-limited components on this, if it turns out to be a bad receiver(eg lack of sensitivity).
I have a question, is this receiver sensitive like all other regenerative receivers? I have never built receivers other than regenerative ones.
30th January 2008 13:25
Any old rectifier should be usable as a varactor in this circuit. I used the 1N4007 because I have hundreds of them, but even a LED should work fine.
You could use a real varactor, like the MV209 available from Kits and Parts, but a power rectifier is a whole bunch cheaper and more common. For this particular receiver you only need a bit of fine tuning, the trimmer does the bulk of the tuning.
30th January 2008 12:58
Again, thanks for publishing a review of this.
I am going to get the 1n4004 diodes for the varactor application.
thanks,
73 de va7aax
29th January 2008 16:29
Thanks for that information Nigel!
Do you happen to know if the ABC or other broadcasters use precision clocks for their TV and FM carriers?
29th January 2008 14:37
Radio Australia at Shepparton uses a rubidium standard to lock each tx's synthesizer. Within the limits imposed by hf propagation it should make a fairly good reference. 5995[14-18UT], 6020, 9580, 9590, 13690 & 15240 kHz are good choices for s-e Australia
The RA broadcasts from Brandon (5995 kHz[08-14UT], 9660 and 12080 kHz) run from TXCO synthesizers - not as good as a rubidium, but ok for checking the bench DFM.
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15th September 2011 13:11
Ray wrote...
Alan,
I built the receiver ugly style very similar to the picture you show. However, I can't get the oscillator running. I've double checked the wiring and it is correct. Any suggestions will be appreciated.
Also, I used a FT37-61 15:3 transformer for L2. I supposed that will be OK. I have a DTC 10 MHz bandpass filter I am going to put ahead of the input once I get the receiver running. I also used 2N3904s instead of the CA3046.