Re: How to teach a Cricket to ...


John Kirby
 

Cricket 80a mods 40, 30
"Where can I get info on the 40 30 mods?  Tnx"  George/W2BPI

HI George,

HAPPY NEW YEAR
    and "may the *qrp*force be with you"  :>)

Credit:
Cricket 80
and
Cricket 80a
design to
David Cripe NMØS
4SQRP Group

The orignal Cricket is cute, clever and delightful enough to own a couple and I do, but like ALL qrp xcvrs there is a weak spot, here it is the xtal osc.

Since David nm0s touts his new 80-a xtal osc and since I was lQQking for a versital osc for my qrss beacon system I decided to bread board his xtal osc circuit. Then all I did was plug in xtals on hand. His 2n7000 osc also works a delight on 40, 30, 20, 15.

As far as I know ...
I am first to try this:
My 80-a's TX components are on a poke board ...

Output is almost two Watts on 40, 30 and 20 with,
Cavaet 1)  12 Volt power supply
Cavaet 2)   Parallel a second 2n7000 (Q2-a) with Q2, note,
                   Q2 is just an on/off switch not an RF amplifier and
                   overheats at 12V   
Cavaet 3)   mod L2, I use xx turns on red T 50-2
Cavaet 4)   mod LPF, I use QRPLabs LPF- band-kit
Cavaet 5)   5 V regulator for Q1 es Q3 2n7000 xtal osc
Cavaet 4)   mod Q7 (add two resistors and 2n7000 Q7-a) such that Q7 no longer in series with Q2||Q2a (at 12V B+ and QRSS 5 sec dits key down I-R drop too great es Q7 overheats). Q7-a now in series with es keys Q2||Q2a.

Works great for QRSS CW, 5 second dit, 15 sec dah.

QRSS FSCW still under construction, but definitely doable with mod at R6/Q3.

I have not modified my 80-a circuit board yet, but I will,  next on the bucket list. . . But first my apologies to David nm0s for mods to such a lovely design and layout. I promise not to destroy your OUTSTANDING 80m L2 / L3 layout, all 80a will remain functional.

If you would like to teach a Cricket to speak QRSS take a pEEk here...

https://groups.io/g/4SQRP/topic/how_to_teach_a_cricket_to/7587611?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,20,7587611

72 73
... es you may share my simple hack with whom ever,
I will copy the 4SQRP Group
John
N3AAZ

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