Old skool SOTA rigs.

Hi Gavin

This does not surprise me, the SST40 is very pleasant on RX, it’s my point of view and reminds me of the reception of QCX (which is an SDR).
Bandwidth is not huge but sufficient for SOTA.

73, Eric

With the SST-20 you had 2 options, either the range from approx. 14055-65 or the range from 14045-14055.
With a switch it was possible to use both ranges…

73s Ingo

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I’ve been using a Kenwood TR751A for 2m ssb/fm recently from summits. Compared with 5w from the 817, 25w really rocks. Although it’s only 5 times the power (7db) it makes quite a difference. It has that classic Kenwood smooth tx audio too.
I have an untested Heath HW7 waiting for attention too. Its case is steel! But painted that nice Heathkit green.
Further down in the junk pile is a Heath 2m AM rig, which has a tube type I can’t recall, a compactron? Some large number of pins, 11 or 12, and would have to be unobtainium these days.
Xtal controlled tx and a tunable receiver. in one box. That would challenge the SDR crowd…

Andrew vk1da

I had an s2s today with Ron’s FT75 on both 80m and 40m. Sounded a lot different to his IC705 but it worked.

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A very nice radio. But the on/off switch combined vol/squelch pot is the renowned failure point on them. The other dual pots can fail but seem to last better. Sadly it’s totally unobtanium from Kenwood and has been for over 10years. You can repair them but it’s uber-fiddly. There’s probably plenty of 751s languishing in cupboards because of this.

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Its just a thought, I like the look of them, I haven’t really decided what I would want, but not the 888 or 888A, I would want general coverage. Long time ago I gave away an 840A and a 740 when I moved to a less roomy house!

True. Pot repairs are complicated. Replacement pots are nowhere but near replacements are available. Ie a dual concentric pot with switch is available as a spare for Ranger CB radios from a US source. Details on the tr751/851 group on groups.io. I obtained some pots there for my radio and got it going again. And very close equivalents are listed on Ali express.
It’s not quite as bad as the nonavailability of 7360 tubes or vernier drives from the TU tuning units made for military gear.
I’ll keep using it while it still works.

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I watched a video on Youtube showing someone dismantling the pots and fixing them. It’s worth that amount of pain if you cannot get anything close. But the fact there are almost matching pots means I may bid on the next 751 I see.

They were on sale when I was first licenced and were a nice shiny thing to own. Then in 1994 theTM-255 came out at £999 in the UK which is £2117 in today’s money. For a 2m multimode! That explains why you hardly ever see them for sale. I’ve seen 3 being sold second hand in 31.5 years licenced!

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Just pulled out the box with all the Elecraft K2 manuals to see when the build of my first K2 was complete: Spring 2000
Hard to believe how quickly these radios age, hi.

That would probably be worth a little celebration, but for me personally it would only be for fun, without any points, rankings or diplomas.

BTW, the first 100 K2 kits were shipped in January 1999.

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Andrew,
Thanks for the QSOs yesterday. The emission of the tubes had dropped and I’m guessing barely 70% . Enough for some fun with the 50 yo FT75. Same or more power than the IC705 but no audio processing.

Being crystal locked on odd frequencies wasn’t a help.

Operating CW was a change. Had to push a button to go from Rx to Rx and ditto back to Rx.

There may be something I need to learn about the tx frequency when I go from 40 m to 20 m. I’ve forgotten and the manual is, um, brief.

Will take it back on the mountains another day.

Maybe with my IC202?

73
Ron
VK3AFW

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I used to live next door to Geoff. See him about the village now and then but don’t think he is ver y active these days.

My hilltop / remote exploits began before SOTA getting inspitation from over the pond and the Wilderness Radio pages of the 00’s and TFR’s being designed.
Have still a SWL SW40, Rock Mite for 40m and 30m, Mizuho MX3.5s and CRKits KN Q7. Had a FT290 (who didn’t) and took that the the summit of Snowdon in the 80’s, IC202, DSW40, to name a few. Sadley my activation raye for SOTA has been dismal. Do also have some more recent kit like qrp DSB trxs and Raspbery Pi for FT8.
If a day were to be arranged I would make an effort to get out but sadly would be SSB as my CW has been neglected in recent years. I am actually collecting vintage portable kit now and expanding the stable when I can.

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I see, that you K2 works on 60m. A friend of mine wants to modify his K2 this way. But didn’t found a source of the module and/or the software update.
Can you tell me more?
73 Chris

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The K2 needs an add on PCB that provides 60m and a 1mW transverter drive, the K60XV. Eleccraft discontinued it some time back due to inability to provide some of the components.

Has your fried tried this route to get the 60m option ?

Or tried seeing if any Elecraft distributors has one in stock still?

I wanted an SSB and transvert board for my K2 and took the cash rich time poor option. I bought a fully loaded K2 (K2, SSB, noise blanker, AF filter, DSP filter, 60m/transvert, 160m, ATU, RTC, IO, battery backup, Heil fist mike, carrying bag and a few km of cables) for peanuts and sold my K2 CW only for big bucks. The reason my K2 fully loaded was cheap was the guy selling it didn’t know about half the options fitted hence the lower than expected price.

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My Mizuho MX 3.5s in action last summer. Not SOTA but high sea cliffs of mid Wales. Did also have an MX 7s that I took to Duncary Beacon but it rained heavily si didn’t set up, but again early 2000 so pre SOTA.

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I recently finished debugging, and adding a @G4TGJ Keyer to, my home brew SST-30.

I had the rig on air yesterday but it seems as though I need to try to re-install the EEPROM file into the keyer chip. Richard’s keyer uses set speeds, there’s a choice of two selected by a switch (uProcessor select pin high or low). The two set speeds are defined during programming of the uProcessor chip and are user selected. To select the speeds, an EEPROM file is written in a simple format defining keyer timing mode, ‘slow’ speed, and ‘fast’ speed. I attempted to select 20wpm for both speeds (I left out the switch) and Iambic B timing. It seems as though I made a goof as my keyer is stuck at 16wpm, the default set by Richard.

I used a cheap ATTINY85 module, via ebay, to implement the G4TGJ keyer, as it was cheaper than buying just the chip singly. The ATTINY85 module is a clone of a Digispark board and contains a voltage regulator, and a USB connector. The USB connector needs to be disabled by removing some resistors, otherwise the keyer doesn’t work. I cut the USB connector portion of my module away in order to squeeze the board into my SST.

I haven’t decided how to try to re-write the EEPROM file yet, maybe I could solder some jumper wires on to the module where I’ve removed the resistors. Or maybe, having just thought about it, Richard’s second default speed is 20wpm, so I could try grounding the sense (switch) pin and see if Richard’s default program is running.

Apart from the slow keyer timing, I’m really happy with the rig, it seems to be pretty sorted now.


Keyer installed in SST, bottom left on this picture.

Digispark clone before extensive modification!

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If your friend built the K2 himself then he will know the history of the Elecraft K2 hardware and firmware versions of the various system and option modules.
This is required because the K60XV option is not comparable to a simple plug and play module, even if the K2 hardware and firmware is at the required level.

The K60XV option was primarily designed to integrate the Elecraft XV50/144/222/432 family of transverters into the K2 system.
Since these transverters have also been discontinued in the meantime, it is to be hoped that someone will offer the K60XV option for sale.
The only problem is that you can’t just unplug this module - if you want the K2 in question to continue to work…

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Tnx for all the infos. I will give it to my friend.

73 Chris

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