Re: About the new Crickett transceiver


Prof. Arnaldo Coro Antich
 

Dear amigo Curt:

Thanks for your very interesting reply to my request. We have achieved nice results on 40 meters using MOSFET devices recycled from computer UPS power supplies that use them as a square wave power oscillator. The CFL NPN transistors are only good up to 80 meters... as demonstrated by many tests, but they simply do not amplify on 40 meters.

Where I can see the circuit diagaram of the Crickett transceiver ?

Here in Cuba we have now 10,000 radio amateurs with maybe 90 percent of them operating on the 2 meters FM segment between 144.2 and 145.800 and using more than 40 repeaters located all over the country. Many of them want to go on the air on the HF bands, especially on 40 meters that provides very nice daytime coverage all over the NVIS coverage area and make possible to work DX during the evenings. The antenna that is most popular here is the 40 meters inverted V dipole, and some hams are using now delta loops...

73 and DX

Arnie  Coro CO2KK


On 30/04/17 12:26, wb8yyy@... [4sqrp] wrote:
Arnie

certainly a Cricket like rig could be made for 40m.  the main feature of this rig is sharing the PA and receive mixer function - this same idea was implemented by NM0S in the Cyclone transceiver a few years ago.  the key device here is a MOSFET -- amazing these little tiny transistors can make 0.5 watts for a 2N7000 or a few watts for a BS170.  this architecture simplifies receive to transmit switching (QSK) also. 

the rest of the transceiver is rather customary - certainly it could be homebrewed.  yes a simple VFO does make some sense here if it is to be used as a regular QRP rig. 

others have wondered if a much cheaper rig could be made with a smaller PC board, without the cute built-in coils? 

I don't know if any consumer devices feature powdered-iron inductors or tiny MOSFETs - but if they did someone could use them for a QRP rig.  I am not sure if the CFL transistors (NPN) would work well o n 40m,&nb sp;

with lower solar flux at more northern latitudes we are finding 40m to sometimes only be good for 'DX' in the evening - hence our growing use of 80m.  yes Spring and Summer mean QRN - and your latitude is closer to a greater frequency of thunder storm QRM. 

CUL 73

Curt

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