UK Radio Rallies

[Squarewave]

Well, the weather isn't looking too chirpy for Sunday over in Ruggers! I wonder what the turn out will be like?

[Zenith]

I don't believe the weather will be boiling hot, like at McMichael and FRARS, which brings it's own problems. My guess is it will be a pleasant enough day, "Sunny periods with occasional showers". But that's no more than a guess. I'll have to find out and feel my bit of seaweed to give a more evidence based prediction.

The turnout will be at least 3; bd139, tggzzz, and me. Shame you can't make it. When I've been there before, it's always been well attended. I assume that with a couple of years of missed events, it will have a lot of visitors who have some rallying to catch up on.

[Zenith]

I may do RATS.

FRARS Duplicated here for the sake of completeness:



HP 204D £10 - working fine needs cleaning.
Farnell TM6 £15 - sort of working. Needs minor repair.
ARRL books £3 for both - selling on ebay
Parts £5 - all good.

tggzzz: I did consider that 465 mule. If I'd moved I'd have had it off you but I was looking for small things

I nearly walked away with a 141T but the RF module was too high a frequency for my interests.

Actually I was looking for a 475 mule and became tempted by the 465 mule. I thought I'd bought a 475 mule a time back, but when I looked at it there was so little wrong with it; a missing heatsink on a hybrid and the delay sweep has had a biff, that I'm now looking for a proper 475 mule. Or at least the heatsink, since the 465 mule would probably provide the delay sweep stuff - mainly a shaft that can't be straightened easily. Anyway, I'm certain I'll be tempted by a 465 that needs a mule.

I saw a 141T just along from tggzzz's stall, but they are huge things, and I haven't looked into them enough to put one on the shopping list, knowing what the plugins are and all the rest. He said he wanted £150 for it. All worth noting. Probably he'd have come down a lot from that because I can imagine he wouldn't want to take it home. OTOH, getting to the car would not have been fun. I doubt you would have walked off with it.

[tggzzz]

I don't believe the weather will be boiling hot, like at McMichael and FRARS, which brings it's own problems. My guess is it will be a pleasant enough day, "Sunny periods with occasional showers". But that's no more than a guess. I'll have to find out and feel my bit of seaweed to give a more evidence based prediction.

The best guide to the weather is to look upwind out the window

Boiling hot means more people go to the beach or somewhere special, rather than to a local fair.

Traders at FRARS reckoned that, so does my daughter - it means there are fewer people to buy ice creams at her local farmers' market. OTOH, hot is excellent at cricket matches

[Squarewave]

.....local farmers' market.....

Now, that's what I think of when people say Hamfest, a farmers market, a farmers fest, where there's ham and other pig related meat.

[Zenith]

I don't believe the weather will be boiling hot, like at McMichael and FRARS, which brings it's own problems. My guess is it will be a pleasant enough day, "Sunny periods with occasional showers". But that's no more than a guess. I'll have to find out and feel my bit of seaweed to give a more evidence based prediction.

The best guide to the weather is to look upwind out the window

Boiling hot means more people go to the beach or somewhere special, rather than to a local fair.

Traders at FRARS reckoned that, so does my daughter - it means there are fewer people to buy ice creams at her local farmers' market. OTOH, hot is excellent at cricket matches

I knew someone who worked for Lyons in the early 60s, in their Organisation & Methods department. Lyons was a very forward looking company - LEO and automated form reading and such.

An important part of their business was ice cream sales, and it would have been extremely valuable to have accurate weather forecasts even a day ahead. So they looked into it and evaluated all sorts of ways of forecasting the weather, including custom Met Office forecasts and all sorts of folk lore. Nothing was off limits.

They came to the conclusion that the best predictor of what the weather would be tomorrow and the day after, was what the weather was today.

Past a certain temperature, I think a lot of people would rather just stay at home and laze around in the garden. Cricket is a different thing.

[bd139]

Can confirm the beach hypothesis.  The little walk we did after FRARS along the coast was crawling with people who had no idea what contour lines are and were slowly dying 

[tggzzz]

Lyons was a very forward looking company - LEO and automated form reading and such.

They came to the conclusion that the best predictor of what the weather would be tomorrow and the day after, was what the weather was today.

Yes, that rule of thumb is oft-quoted, and (in the absence of better information) you won't get a better estimate.

Merkins, in particular, tend to disbelieve that the first business use of computer in the world (the Lyons Electronic Office 1) was in effect venture capital funded by a "tea and cake" shop.

On 15 February 1951 the [LEO 1] computer, carrying out a simple test program, was shown to HRH Princess Elizabeth. The first business application to be run on LEO was Bakery Valuations, which computed the costs of ingredients used in bread and cakes. This was successfully run on 5 September 1951, and LEO took over Bakery Valuations calculations completely on 29–30 November 1951
...
Lyons used LEO I initially for valuation jobs, but its role was extended to include payroll, inventory, and so on. One of its early tasks was the elaboration of daily orders which were phoned in every afternoon by the shops and used to calculate the overnight production requirements, assembly instructions, delivery schedules, invoices, costings, and management reports. This was the first instance of an integrated management information system

[Squarewave]

All set for Ruggers tomorrow then, chaps?

[bd139]

Not going to this one. Too busy moving house and stuff. Will do MKARS next week.

[tggzzz]

All set for Ruggers tomorrow then, chaps?

Yes. Unless I forget to wake up.

[Zenith]

Yes, all being well.

Accuweather says "19C Intervals of clouds and sunshine" - they are usually fairly accurate 24 hours ahead.

Should be a pleasant day.

[Squarewave]

I can't go today, but hope it's a good one. It's been years since I went. The Rugby rally is where my Marconi TF144H/4S came from. I rebuilt the power supply as a part of its restoration and since, it's been my main vintage signal generator in my lab.

[Zenith]

I'd say, not up to expectations. Nowhere near as much tempting junk as at McMichael or FRARS, and certainly not to be compared with Newbury. I recall it was better in previous years, and better attended. The weather was very pleasant.

There were the obligatory tatty AR88 and codged R1155, without which no rally could call itself a rally. There was a Philips Electronics Engineer kit for £25. I had one as a kid, but I have no hankering for one - but still nice to see. There was an HP AF spectrum analyser, but no other SAs. There were a few scopes I had no particular interest in.

I came away with a couple of valves, some components and bits and pieces, some SMC leads and a BNC/SMC adapter. I also scored a Racal 5MHz OXCO for £3.50 which I was assured was brand new, but judging from the solder on the pins, is previously enjoyed.

tggzzz was there and had a better day from the point of view of acquisitions.

There was nothing on my shopping list and no £5/£10 bargain bit of TE for another winter project. I'm glad I didn't miss it, and it was a pleasant day out, but if you wanted to go and couldn't, don't reproach yourself too much.

[bd139]

Thanks for the review. Glad I didn’t bother if I’m honest.

Good luck with the racal OCXO. I gave up on one here  https://www.eevblog.com/forum/testgear/repairing-off-frequency-racal-9442-ocxo/

[Zenith]

Had you been there, you might have spotted things I didn't - but my general opinion is that it was a bit flat. Since you are in the middle of a house move, I'd say it wouldn't have been worth the trip for you.

As for the OCXO, it was £3.50 and the seller had an honest face - they're always the worst. It's soldered in its can. I'll see what it can do when I get round to looking at it.

[tggzzz]

I've not been to Rugby hamfest before, so can't compare.

The footfall wasn't very high. I lost money, even excluding petrol.

But then that wasn't the reason I went.

For £90 I came away with

• HP654A oscillator. Works but could do with a little tweaking
• Picoscope differential probe 25MHz, /10 /100. I already have a /20 /200 diff probe, but this requires fewer brain cells. Works on internal batteries
• Advance OFS2B off-air receiver. Looks like it receives and locks, but no output. I'll assume its guts are similar to my other receiver, and hack it
• Tek 468, which looks like a 456B with a wart glued on. Wart contains a 40MS/s digitiser plus voltage and time cursors. Works, but guess what needs cleaning. Weighs >30lbs

Eventually I'll put pictures on That Other Thread.

[Zenith]

Good luck with the racal OCXO. I gave up on one here  https://www.eevblog.com/forum/testgear/repairing-off-frequency-racal-9442-ocxo/

This one is 9 Hz down at the upper limit of adjustment.

I wonder how you desolder these things.

[bd139]

Can opener 

[Zenith]

Unlike corned beef, they don't come with a key.

As this thing cost about the price of a pint in a pub, and the innards are used to being cooked to 70C, and picking up the odd dud is all part of life's rich pageant. I think I'll try making up a thing to pull the innards out using the mounting screw holes, fixing it in a vice, and then going round it cautiously with a blowlamp.

[bd139]

Sounds sensible. Interested to see the results and contents.

Not sure where you live but pints cost twice that here 

[tggzzz]

This one is 9 Hz down at the upper limit of adjustment.

Obvious question: compared with what?

[Zenith]

This one is 9 Hz down at the upper limit of adjustment.

Obvious question: compared with what?

5MHz as shown on a couple of Racal frequency counters which show 10MHz to about 1 digit when connected to a GPSDO.

I connected a 10 turn 10k preset pot across the 12V supply with the wiper connected to the VCO pin, and the adjustment range is about 7 Hz from 9.999984MHz to 9.999991MHz. I assumed that would be the voltage range the VCO was designed for.  I couldn't find anything on the WWW about this particular Racal OCXO.

It takes more current when the oven is cold, and the unit gets warm to the touch, so I assume the oven is OK. I suppose it might be under temperature for some reason.

I'd guess the crystal has aged out of range. It could be a trimming capacitor which has changed value.

[bd139]

Possible. Might be possible to shift it up a bit but it would involve replacing a capacitor and reducing overall capacitance in the network. Was hoping in my original one that I could tack a couple of pF on the bottom of the board. That was until I realised it'd go the wrong way 

Still arguing with my Farnell TM6 here...

[Squarewave]

Sounds like an OK day though. When I went to the Rugby rally last time, I don't think I bought much apart from that Marconi signal generator and also a Marconi chewb volt meter.

MK next week then chaps, nothing in particular on my shopping list, just want to have a browse around and see what takes my fancy if anything at all.