Trio TS930

[its ur aerial]

I have been offered a Trio TS930, in working condition, but I read on the net, they all suffer with switch mode power supply problems and Fan temperature sensor failure.
Would these issues be a strong enough reason to pass up, on the offer?
What years were they manufactured ?
Seller wants £250 ono ?
Ken G6HZG.

[Radio Wrangler]

You can read all sorts of bad things on the net about everything you could buy to the point where you should wonder why anyone ever buys anything. "They all suffer..." sounds like you are expecting it to fail, so it would be inconsistent to pay more than what you would consider scrap value.

Back in the middle 1980s, they were seen as quite decent quality 'flagship' rigs and had a high reputation in the UK. It was replaced by the 940, 950 roughly as a series. But the Trio corporation goofed. They made an error in choosing the loop filter time constants in their synthesiser and their own official UK importer of the time started offering, for a fee, after-market modification to improve the radios. It was bad enough to degrade the close-in selectivity. Those in the know went for the ICOM IC-761 and IC-765 which is a 761 with some useful improvements, or they stuck with their TS-930s which might have lacked some newer features, but were better performers.

1980s power supplies were relatively fragile. If one goes bang nowadays, you won't find stocks of the switching transistors and the controller ICs waiting for you to order one. They are likely fixable, but you'd have to get inventive to substitute something obtainable. I did once fix the SMPS in an IC-761 but this had been bought by an American in California and moved with his household goods when he moved to Australia where it was plugged straight into 220v mains while still set for 120v. He never got it fixed before his job moved him to Scotland with the now-dead radio once more in his relocated possessions. It was popped into a shop for repair and he was told that everything internally had been overvoltaged and that he should buy a new TS950!

I had a look at it. The set was powered from 13.8v internally and worked just fine with an external 13.8v supply connected in. Only the SMPS was dead and bits of plastic were blown off the packages of the two chopper transistors and their controller/driver IC. Spares were then got from Icom UK and the fix was successful. 100% function restored. This PSU did not fail, it was destroyed by human error. However, the parts I then used are no longer available, all stocks long since used.

But you can get around SMPS failures in this generation of equipment if you want to do so enough, or you can just convert it to use an external 13.8v supply. These sets pre-date the usage of higher voltage RF output transistors, so I think the TS930 will run on 13.8v only. I know the Icom can.

In the early 90's I decided to buy a good quality HF radio. Candidates were the TS-940, TS-950, IC765, FT1000D. I had a session checking performance of some loaners in the labs at HP. I bought an IC-765. I still have it and haven't been disappointed. It needed the trimmer capacitors in the final synthesiser loop replacing after about 20 years (the anti-vibration compound slowly rots them in all big-3 brands) and it currently needs some of my time to replace a failed CMOS logic gate in the T/R switching circuitry.

The FT1000D offers dual receivers, which I find more confusing than helpful. I've only got one brain and one train of thought. The FT1000D offers 200W output, but my licence then covered 400W and linear amps are designed around 100W drive. The 765 has a speech processor which actually gets compliments on-air! and that levels things up a bit.

The FT1000D offers filter responses giving much sharper, squarer-cornered filter responses. They make a big thing in their brochures. They ring! The Kenwood filters have better chosen shapes for intelligibility, as has the IC765. I've seen it written since that Icom cheapened off their filters. Having bought a set of the narrow option ones for both 455kHz and 9MHz IFs, cheap isn't the word I used at the time. No, thie graphs look less impressive because they knew what they were doing. Yaesu were engineering a graph they could point at for marketing, at the expense of function.

So, any of the flagship rigs of this era have SMPS worries. They are not insurmountable but can be quite a nuisance.

Kenwood (Trio corporation is the name of the parent company, Kenwood is a brand name they use in countries where they didn't fear litigation from food mixers) Have had a higher reputation in the UK than their stuff really deserves. Icom had blown it in their generation before the IC-761 by having software held in battery powered static RAM chips, so some distrust lingered. It was a stupid thing to do. The Yaesu was designed to look overwhelming on paper, it was quite good, but when used, fell short of the promises.
The IC-765 is generally seen as a star, and second hand prices are pumped up by the very favourable reviews all over the internet.

So there you have it, the main top end rigs of the era compared. None of them perfect.

Another good radio of the period is the Ten Tec Corsair II. rather different to the japanese sets, but quite a performer. Not perfect either, but a golden oldie.

The set you've been offered is still a worker so even after all this time, the SMPS reputation hasn't killed it, but then if you bought it, who knows what the future will bring?

There is risk involved. Whatever the price is, it is a gamble. Never gamble more than you can afford to lose. This is a decision no-one else can help you with.

David

[Terry_VK5TM]

The TS930 power supply is all discrete components, not SMPS.

Also it will not run off 13.8V as it needs 28V for the PA.

https://www.dl8rds.de/images/1/1b/TS930S_PSU_Analysis_and_Improvement.pdf

[Radio Wrangler]

Thanks, Terry. The mention of switch mode in the first post must have thrown me. I've been in all these sets to sort various problems, so it's easy to get confused over which one has what. If it's got a linear power supply and a big iron transformer, then it ought to be straight-forward to fix if it goes wrong, and this one is still working. Temperature sensors for fan speed controllers aren't rocket science. There are some neat sensors from ADI.

The set just needs some care in siting so that it can easily get good cool air to weight the odds favourably.

My apologies

David

[Terry_VK5TM]

No apology needed David, I had to go and check myself which supply was in it as I too saw the mention of switch mode in the OP's post.

For the OP, they were made from early 1980's to the end of the 1980's.

£250 is a reasonable price if it has no faults and is in fair cosmetic condition.

[its ur aerial]

Thanks to Terry and David, if it hasn't got a SMPS with unobtainable semi conductors, then I am now a lot more interested in the unit .
I did have a long brake from Amateur Radio, so I am not that familiar with equipment from the 80`an 90`s.

I did read several reviews that mentioned it having a SWPS, all posts originating from the USA, did the 110v version have a different PS, or are they talking ? Probably the later. As David mentionens, the Fan sensors can`t be rocket science to sort out.

Thanks again, much appreciated ,

Ken, G6HZG.

[Terry_VK5TM]

You might want to have a look at this also, has some relevant info on TS930 faults plus some service bulletins.

https://w3afc.com/uploads/3/5/9/3/35934954/a_compendium_of_i...your_own_kenwood_ts-930s_rev_7a.pdf

[its ur aerial]

Terry, thanks for that info, really useful.

73`s,
Ken, G6HZG.

[Draker4c]

Probably worth going on the groups 10 ts940 and 930 site. There are replacement smpsu available from suppliers there which might have generated the confusion between these being present in those rigs. The original in both the 930 and 940 are linear psus

[its ur aerial]

Thanks Draker4c, i have found the users Group, and have applied for membership.
73`s
Ken G6HZG.