Trio 9R-59DS communications receiver (1970)

[Phil G4SPZ]

Originally Posted by turretslug

I wonder if a bit of creativity with tin snips and food tins etc. would make a workable substitute?

The sleeves in the photos do indeed look just like they have been made from the corrugated material from a 'tin' food can. However I've got some proper matt black aluminium valve covers somewhere which will look better and also radiate a little more of the internal heat.

The previous owner has kindly been in touch, and confirmed that three metal sleeves were indeed originally fitted, but caused the valves to run very hot, so he opted for a bit of drift rather than cooked valves - I think I would have done the same.

[turretslug]

I was especially "impressed" by the underside shot that warned about not fitting one of the fixing screws- in case it contacted said filter and there was a flash, a click and everything goes off on a Finnish winter's night...

Still, it gives a fair few overall shots from different angles.

[Andrew2]

Originally Posted by Phil G4SPZ

If I had ever done work as untidily as that, I would certainly not have publicised it! Has the perpetrator no pride? I wonder what he does for a day job? Butcher, probably

Probably not. Some people are like that. I never cease to be amazed by some of the pictures of homebrew projects sent into Practical Wireless - I would be ashamed to build something like that at all, never mind take pictures and send them to a magazine!

[Radio Wrangler]

That used to be pretty much the normal standard of amateur radio construction in all the British magazines I got. In the era I came across a few copies of American magazines like 'Ham Radio' and I was shocked by how good looking the construction of all their projects was. There were honourable exceptions this side of the pond, of course... Just look back at the G2DAF articles on his receiver and transmitter. I wonder if anyone has examples of those preserved for posterity?

David

[Simon_V]

Originally Posted by Phil G4SPZ

I was given this early 1970s valved communications receiver by my very good and generous friend Phil Cadman G4JCP, who had owned it from new, but as the set had spent the last 25 years unused in his loft he felt it needed a bit of TLC and a new home. This type of set is a bit outside my normal ‘comfort zone’ when dealing with vintage valve radios, but Phil twisted my arm and I have spent the past week working on it. It had several faults including a couple I had not encountered before, so I thought I’d share the story with you

Good read Phil

I am another one who had one of these as his first set. My uncle had one and I used to sit there for hours listening to QSO's on 80M. I think my parents finally realised that this obsesion with radio's was not going away and by this time they were used to various bits of wire being strung up along the length of the garden. My dad and I spent months making a weekend trip over to Alum Rock (Birmingham) in search of my 9R59DS.

So you know Phil Cadman G4JCP. I have known Phil since he was G8HHK (He is going to hate me for that) It's down to Phil and some of his friends that got me into Amateur Radio in my early teens. It was also Phil who sparked my interest in computers.

I really must get around to re-validating my licence but for the record I am Simon G6TKK although as I now live in West Wales I guess I am GW6TKK

Regards

Simon

[Phil G4SPZ]

Go for it, then, Simon! Glad to see that this thread has evoked mostly happy memories of these receivers.

I'll pass on your regards to Phil next time I see him.

[Simon_V]

Happy memories all round really Phil

underage drinking after radio club nights and some good people who got me into amateur radio and guided me through my SWL days. If you know Phil then you probably know some of the others as well.

Gordon G4DGM
John G3XEV
Dave G3ZPF
John G3YZP
Alan - Was G8LAV can't remember his G4 callsign
Bob G3PWJ
Jeff G3ZGY
Jim G4EIB R.I.P.
Jim G3SIO

They were great times and I learnt a huge amount from these guys.

Regards

Simon GW6TKK

[Phil G4SPZ]

I do know DGM, XEV, ZPF and PWJ. They still have a local weekly net with G4JCP on a Monday night on 2 metres.

[Phil G4SPZ]

Just an update to this thread, I was contacted by e-mail a while ago by Jean-Pierre ON4AEF, and I have been advising him on his own restoration and realignment of one of these sets. He also seems to have the same problem with 'deafness' and his set's LO amplitude is way down as well. Hopefully he'll be able to remove that awful wax from the LO coils.

[G6Tanuki]

It's good to know that knowledge is being passed-on down the decades!

A curse on those who deployed nasty Q-sapping wax (even if they didn't know what it would degrade and annoy us 40-years down the line).

[Phil G4SPZ]

Originally Posted by G6Tanuki

A curse on those who deployed nasty Q-sapping wax (even if they didn't know what it would degrade and annoy us 40-years down the line).

I'm sure they didn't do it on purpose, despite the possibility of 'planned obsolescence' being well-established in the late 1960s. To Trio's credit, they didn't use any Hunts waxies although by this era the polystyrene capacitor was starting to become the Hunts's successor.

It's quite possible that this wax survives better under different storage conditions. However, I've not come across the phenomenon before, in any set from the late 1920s onwards. Perhaps cost-cutting led Trio to try a cheaper type of wax. You see waxy substances blobbed generously around the PCBs of later transistorised equipment, and even present-day electronics of far eastern origin is festooned with blobs of what looks like hot glue. How long before this stuff starts to deteriorate and cause strange faults? It's fascinating to speculate. However, back on topic, my correspondent ON4AEF has now removed the nasty wax and achieved better performance, although his receiver is still rather deaf on the 10-30MHz band. Once his set is fixed, I'll report back on any new and useful information.

[deliverance]

Very interesting write up well done .

[Phil G4SPZ]

Thank you very much! It's surprising how much interest this thread has generated, and proves the value of posting these reports on the Forum as they are found by search engines and read internationally. As well as my Belgian contact, I have since been approached for advice by ZL1ER in New Zealand, who is also restoring one of these sets.

For what it's worth, I was listening to my receiver for a couple of hours last night, and it remained very stable whilst I was overhauling a signal generator.

[Andrew2]

I bought myself one of these brand-new in about 1972/3. It cost me £45 and IIRC it was ready fitted with the voltage stabiliser and the xtal calibrator (but no xtal).
It was the first 'proper' comms rx I'd ever had, previously making do with domestic sets and very cheap 'Knight Kit' types.
It was pretty decent apart from the fixed IF filter-width and the drift. On the lower bands it was fairly stable, but the higher ones suffered from a constant drift and it would also 'pull' off frequency when confronted with a strong signal, judicious use of the RF gain pot was a must. I made the mistake of fitting an internal speaker, but it just caused howl-round when I turned up the wick!
Many years later (when I'd got a very nice Trio R-1000) I lent it to a budding ham who never gave it back.

[jclassic1]

I have never owned a shortwave receiver but for some reason I have always been interested. Now I am retired I feel it is time to get myself an old reasonably easy to use SW radio set, and find out more about it.
I am looking at this radio as it seems to be ideal for a beginner to get started, and it seems to have been and probably still is a very popular set.

John

[Hermit6345]

Good write-up Phil. I had one of these from new in the early seventies. Although I fitted the voltage regulator valve, it didn't solve my drift problem. I used the receiver as a tuneable IF covering AFAIR , 4 - 6MHz., this covering the whole of the 2m band.

From time to time the receiver would suddenly drift off frequency. I finally got round to monitoring the mains voltage. It would suddenly drop and return to normal after a few minutes. I guessed that the valve heaters must have been changing temperature each time that the mains dipped. We lived at the end of a long electricity spur and each time that the deep freezer cut in, the fault appeared. The solution, after a lot of head scratching, was to fit an Advance Voltstat CVT in the mains supply for the Trio. That did the trick and I used that receiver for many years until an FR400dx replaced it. Your write-up brought back some happy memories from way back then. Thanks.

[Phil G4SPZ]

John,

Yes, if you can find one of these sets it would certainly give you a lot of fun. They are quite capable, despite their known limitations, and are 'relatively' easy to repair.

Hermit,

Many thanks for your kind comments. I had a similar issue with poor mains voltage stability causing drift, so I run my Trio off a CVT as well. I suspect that certain examples of valve are more sensitive to heater voltage fluctuation than others.

[Skywave]

Valve heater voltage variation: not everyone has - or can lay their hands on - a CVT.
Idea: bridge rectify the heater supply from the transformer, feed it to a d.c. voltage regulator and thus to the heaters. A provision for heater in-rush current will be required: perhaps a soft-start cct. An over-voltage crowbar on that regulator O/P would be a good idea too.

Al.

[Phil G4SPZ]

Indeed, Al, but that would be a modification, which I don't want to do, as I eluded to in post #13. As David so aptly put it in post #14, "I think the greatest value, now, of a 9R59DS is in keeping it original as an illustration of how things were. In days gone by it was different."

And besides, I already have a CVT so I might as well make use of it!

[Skywave]

Fair comment, Phil. It's your radio: your right to repair it as you see fit.

Me? My attitude with most mass produced electronic items is that they were made to a cost limit - which, from a manufacturer's viewpoint, seems quite reasonable. However, if I find what I consider to be a defect or a short-coming in a design, I'll seriously think about wading in and effecting a change.
This is not a question of 'right or wrong' - simply a matter of personal taste and attitude: each to his own, etc.

Al.