Hi Fellas:
At 07:51 AM 6/19/2005, walter renner wrote:
I have used my K2 with and SB1000 Heathkit amp (3-500 single) with good
results, about 120 watts out on SSB and have had good reports. I have
also used it with an Ameritron AL811 (3 811As) and this gives about 135
watts out with 15 watts drive, again with good reports. This has been on
75 meters where I check in to local nests.
K0ARO
Kurt
For what it may be worth...
Several YEARS ago, Elecraft posted to their web site that I was working on
a PC board adapter for the BASIC K2 (e.g. 15W, no K60XV installed) to add
the ability for it to key an external T-R relay such as those in QRP RF
Amplifiers.
Well, I think a PC board design was posted somewhere, but it never breathed
the light of day as far as ever going into production. Additionally,
another reflector member had a small run of T-R PC boards run off and they
found their way to Elecraft for sale. Once those boards (and associated
parts) went out the Elecraft door, they (Elecraft) continued selling 'kits'
of parts only (no PC board) with which you could wire your own external T-R
relay driver, but no PC board was available as far as I know.
Recently, I have redesigned the PC board for my external T-R relay driver.
I've sent out three Field Test (prototype) boards three builders. Tow of
the boards are still awaiting the builders to complete their RF amplifiers,
BUT the third board HAS been installed and is merrily keying an Alpha
amplifier... I don't recall the specific Alpha model however.
The PC board design uses two resistors, one 2N7000 MOSFET in the
pre-driver, and either one 2N7000 MOSFET (60VDC and 150mA keying current)
or a heavier-duty
HexFET (200VDC and 5A keying current) at the output. You can choose which
output device to use.
I will place the documentation for this PC board design on my web site at:
www.n0ss.net
The file will be in (1.4MB) PDF format and will be located in the section
entitled "K2 RELATED FILES", but you can use the QuikLinks at (almost) the
top of the page go directly to that section by clicking on the "K2-SPECIFIC
FILES" link. By the way, the pix on the docs show the heavy-duty HexFET
model of the adapter.
Parts for this project ARE already available (I think) available at
Elecraft, and they can also be ordered from Mouser (both Elecraft and
Mouser part #'s are included in my docs). And I'm hoping that Elecraft will
decide to have some of these boards made and include them as part of the
'kit' of parts they currently offer. I sent a design to Eric at Elecraft on
Friday, but I used a drafting program I'm not familiar with (ExpressPCB),
so I may have botched the design enough that I'll have to re-do it before
they can use it (IF they decide to use it). In the meantime, if there's
enough interest, I'll consider making some PC boards up (it's a 'kitchen
sink operation' here, so they're not quite as 'pretty' as those
commercially made, but they do look quite nice and work just as well).
Price of the PC boards will probably by $6 ppd to your (US) doorstep with
another $1 for DX orders. Please contact me directly if you are the least
bit interested... I do NOT have any boards made at present, and am hoping
that Elecraft will pick them up BEFORE I have to drag out the light box,
developer and etchant... <G>
Just thought someone might be interested.
ONE MORE ITEM... If you use this device you WILL have to have
one of the more current PIC firmware versions.. once which
allows you to set the MENU item "T-R" to "8r hold" using the
[DISPLAY] button once you are in the T-R edit mode. I don't
recall what firmware revision first offered this feature, but
it is a requirement if you wish to use the K2's 8R line to key
an external T-R device.
73,
Tom Hammond N0SS
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