[VHFcontesting] Elecraft transverter question

[Colin Haig (VE3MSC)]

For the record... here's what I did to my 3 XV transverters to solve issues
similar to Mike.

Heat problem - solved by replacing thermal pad between heat spreader 
and case. Use Thermalcote heatsink grease instead.

Scraped paint off the case under screw heads, using a cylindrical 
dremel bit, for all 3 XVs. Replaced the black screws with chrome or 
stainless on the XV432. This helped the output substantially.

XV144 - the supplied crystal is out of range, and Elecraft will be 
replacing. Turns out they started using same one for XV144 and the 
internal K144XV. But XV144 will be more than 10KHz off, so you can't 
correct for it.  I added a small series variable inductor between 
xtal and ground, and this helped me get it within 5KHz. You can't 
bend these crystals very far.

XV222 - I removed L19, jumpered it out, and replaced C12 with a 
variable capacitor. Schematic says 12pF, assembly guide 18pF, and a 
variable let me get the frequency within a few hertz.

XV432 - drilled a couple holes near U6 and jumpered top to bottom. 
There just arent enough vias on this board. Replaced my U6. Output 
now pretty stable. I still think PA Bias instructions in alignment 
are wrong for this unit.
Fan wires would not go through the big via, so I soldered it at the 
diode on the top of the board.

Already sent to him privately.
73,
Colin VE3MSC

-----Original Message-----
From: VHFcontesting <vhfcontesting-bounces at contesting.com> On Behalf Of Chet
S
Sent: December 7, 2019 11:05 AM
To: vhfcontesting at contesting.com
Subject: Re: [VHFcontesting] Elecraft transverter question

Mike,

FWIW, the schematic for mine shows no variable cap and the Elecraft booklet
says "The oscillator in XV222 is not adjustable, the firmware in an Elecraft
K2 or
K3 transceiver allows you to compensate for frequency errors using the menu
commands."

73,
Chet N8RA


-----Original Message-----
From: VHFcontesting <vhfcontesting-bounces at contesting.com> On Behalf Of mike
repinski via VHFcontesting
Sent: Saturday, December 7, 2019 10:26 AM
To: vhfcontesting at contesting.com
Subject: [VHFcontesting] Elecraft transverter question

I have a Elecraft 222 mhz transverter that I am going to interface with my
TS-940 Kenwood. The frequency of the transverter is off about 8 kc. when
used with my K2 radio. Looking at the schematics for the 6 meter transverter
they have a variable cap to net the frequency. Is there any reason not to do
this for the 222 transverter? Any suggestions? Thanks Mike, See you on 222.
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