Vintage Audio Activities...

[mickthemaverick]

Goes well with my pirate radio:

BFTW

[CitroJim]

to both of those...

[Peter.N.]

The ham one should have some mustard.

Peter

[CitroJim]

The ham one should have some mustard.

Nice one Peter And I hope it's well cured!

Do you remember when the term 'ham radio' was not appreciated and seen as a bit disparaging, giving the impression we were all like Tony Hancock's character and a bit of a joke?

Nowadays it's very much back in vogue although I'm not keen. It's Amateur Radio to me, always has been and always will be...

And... 'HAM' was an acronym at one time for a 'Half-Ar$ed Mechanic'

[Peter.N.]

I think there are so few of us about now Jim that most people don't know what we are! Especially on 2m.

Peter

[CitroJim]

Yes, that's true Peter...

[Paul-R]

Our radio club is gradually shrinking. Natural attrition is the cause and it's been quite a while since someone new joined. Even then it wasn't a youngster.

When the club was formed in the 80s we were the young Turks. Now we're the SOTs (sad old tossers), Our average age must be in the 60s if not 70s by now. The Christmas meal attendance is getting smaller and smaller as we need fewer tables to sit at!

[CitroJim]

When the club was formed in the 80s we were the young Turks.

Yes, i was one of those back in the late 70s and early 80s Paul.. Our once thriving radio club is virtually defunct now...

I see the UK Vintage Radio and Repair Forum is currently conducting an age poll. Most members are between 60 and 80 it seems...

The only meal tables that don't seem to shrink are our post-retiree 'Old Boys' meets at our local carvery every month... Seems my old career goes on to ensure a long post-work life!

[xantia_v6]

My late father and I have owned these two objects for more than 50 and 70 years, but this is the first time that they have been together.

The book is from 1952. How a 1950 era HT generator got to New Zealand (which never had 405 line TV) is a mistery. I know that there were some demonstrations of CCTV in the 1950s.

[Peter.N.]

Philips 25kv EHT generator using 3x EY51 in a Tripler circuit. Remember them well, dreadful regulation.

Peter.

[CitroJim]

Philips 25kv EHT generator using 3x EY51 in a Tripler circuit. Remember them well, dreadful regulation.

Peter.

I recognised that instantly! I had a similar one as a kid when I was given a 1950s projection TV using the little MW6-2 projection tube and optics requiring 25Kv EHT...

Amazingly I survived not killing myself with it Still, those EHT generators were a little safer than the mains-derived EHT generators of the time - 'safety' maybe being a relative term...

Mains-derived EHT generators are still very much in use today and almost every home has one in the form of a microwave oven. They continue to be lethal if mis-handled and many have been killed trying to fix a faulty one...

[Peter.N.]

We had quite a number of customers with the Philips back projection set's Jim and I at one time had a Decca forward projection and that used the same unit. I don't think the output was instantly lethal as the available current was very low, so much so that you could adjust the focus with the brightness control!
The HT though was, if you recall it had two PZ30's giving positive and negative voltage rails that was 400v at some current, I never personally got bitten by one of those as they were the preserve of the other engineer.

They were very complicated though with beam suppression so that they couldn't display anything unless both time bases were working other wise you got a horizontal/vertical line or spot burnt on the CRT - expensive. Made fault finding difficult though, you really needed a scope to see if the time bases were running, I don't think we had one in those days.

I often wonder what our other engineer would have made of the sets we have now. He died about the time transistors came in.

Quite nostalgic seeing that Jim.

Peter

[CitroJim]

if you recall it had two PZ30's giving positive and negative voltage rails that was 400v at some current, I never personally got bitten by one of those as they were the preserve of the other engineer.

Now that would have properly bitten!

They were very complicated though with beam suppression so that they couldn't display anything unless both time bases were working other wise you got a horizontal/vertical line or spot burnt on the CRT - expensive.

I think that's one reason I never managed to get the one I had going Peter, I was unaware of the beam suppression until much, much later!

I kept the optics and tube for years and found them again when I cleared the attic of my parent's bungalow in 2005. I scrapped them and wish I hadn't now...

I love a bit of old TV nostalgia Peter, they were such a major part of my young life and the TV subforum in the Vintage Radio forum is my favourite part of it

[Peter.N.]

Philips were very good at innovation Jim, some of their pre war radios only used three valves and got as good or better performance as others that had five. Their tuned circuits were second to none. They made a TRF that performed as well as a superhet, I had one once. The tuning was every bit as sharp and it would actually work without an aerial plugged in.

The first transistor car radios they produced only used four transistors maybe plus a PA, don't remember but the performance was brilliant. They made a pre war radio with a tone control that actually altered the bandwidth, it had a metal slug moved via a Bowden cable, in and out of an IF transformer.
The also made the 'Mono knob' set, all driven by Bowden cables, rotate to tune, move from side to side for volume and up and down for tone. Mind you the cables were a pig to repair if they broke.

I won't go on

Peter

[xantia_v6]

For my birthday I got a tweezer LCR meter. I wanted one for making in-circuit checks of capacitors. It measures capacitance and ESR.

It's first job was to check the capacitors in a bathroom fan timer module which was intermittently not turning off. It found that the 250V 220nF capacitor used for dropping the mains to 12V was down to 70nf,

Today I remembered that I had a 240V Dremel which failed last year, just not running. I found 2 electrolytic capacitors on the control board, a 1?F which measures 770nF with 55? ESR and a 100?F which measures 19?F with 75? ESR. For comparison, a new cap from my junk box has an ESR of 0.5?.

I am very happy with this gadget.