Re: FrankenCricket - It's alive!

wa2cky
 

Nice work and thank you, Dave, for your report!  I also have a 'unfinished' Cricket and maybe I will upgrade to the 80A level .... or maybe I'll just buy a new one!  One thing that would be handy would a list of any new parts that are needed to do the conversion - it is always handy to have what you need already on hand.

73
Bob Groh, WA2CKY

On Tue, Dec 5, 2017 at 10:06 AM, n4elm@... [4sqrp] <4sqrp@...> wrote:
 

After Ozarkcon 2017, I ordered and received a Cricket 80 kit and stuck it on the shelf for "later".

The open board design was OK but I thought I might want to build one into a box so I ordered additional parts from overseas and from Tanner's (Carrolton, TX) on my occasional trips up to see the grandkids.

Recently I saw that the kit had been upgraded to the 80A, so I figured out the additional parts needed and after the most recent trip to see the grandkids had all the parts together and thought I could implement the new 80A circuit on the older 80 PCB.

Last Sunday, I opened up the Cricket kit, looked through the baggies of parts and realized that the kit had no semiconductor parts - no diodes, FETs, or IC!


NO BRAINS, the Cricket had NO BRAINS! Must have BRAINS!


Wait! I had a complete set of parts on hand for the additional Cricket in a Box project, so I did a BRAINS transplant to the PCB and after cutting traces (sometimes the wrong ones), swapping parts, bridging traces, and running new wires, FrankenCricket lives!

It puts out 1/2 watt and receives signals using several of the 80 meter crystals that I have. 


I would not recommend modding the 80 PCB to a 80A. It really takes some careful planning of the trace cuts, new wires, and parts placement which I did not do well. 


I used the 80A schematic for the build and found that D1 is reversed on the schematic.

The D1 cathode needs to be connected to the junction of Q4 & C18 to unmute the audio in receive properly.

I used an on-hand 68 uh choke for L4.

I used a small ceramic 22 pf trimmer for C15 to allow the receive offset to be shifted slightly.


I copied a couple of picture up to the files section, its not too pretty but it seems to work!


So be listening for a chirping Cricket from the bayous of Louisiana!


73 - Dave, N4ELM



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