[Elecraft] 4mhz and C22 bandspread.

[Ron ZL1TW]

Ken Brown wrote:

<I need to compare notes with anyone who has done the
<bandspread mod C22 + X2 crystal (C21 replacement)

Today was a typical wet Spring day here and with nothing better to do, I
decided to have a go at the bandspreading mod
as outlined  by John KI6WX (ie the replacement of C21 with a 10pf N750 , and
another 10pf N750 across X2)
The mod went Ok and I was certainly able to align C22 better , but didn't
quite have the range I needed, so  changed the 10pf across  X2 with a 6.8pf.
This time I had sufficient range and the alignment  and Cal PLL went
well.....or so it seemed.
However.....this evening I fired the rig up to work a sked, and the ATU
seemed strangely reluctant to obtain a match.
When I transmitted CW , the telephone out in the Lounge started ringing in
unison with each dit and dah, and the computer screen here went nuts and
pulled down all sorts of windows!! needless to say I didn't transmit long.
I checked the general installation and it seemed OK. I tried another
transmitter on the antenna and the SWR was fine, so I pulled the Control
board out again and replaced the original C21 and removed the cap across X2.
After realignment and Cal PLL, , the rig worked fine again.
Obviously the mod didn't work for me ....appeared fine on receive.....but
something wasn't right on transmit.
The mod obviously works OK for John, but my rig didn't like it, so C21 will
be staying "stock" from now on.
I post this message  FYI and not a critism of  the mod. YMMV.

73......Ron ZL1TW