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Caddy

Has anyone ever heard of one of these?

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571B336F-7E91-4CB8-9B32-7FD9C8045AB3-3222-0000024BCB25C630.jpg

 

Just got one for free.

Mains powered, with what seems to be an oscilloscope, and variable voltage selection.

Wondering if it's an old line tester.......

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Any chance of a front panel photo - and any information as to where or what it came from?

 

The style of the label looks 1960s or early 1970s prior to GEC taking over Marconi.

 

I'd guess based on very little info that it is a waveform monitor used to check modulation on an HF radio transmitter - this is effectively a simple oscilloscope.

 

Regards

 

Iain

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A front panel photo would have been a good idea wouldn't it, I don't know why I didn't. I'll take one on Tuesday.

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Any chance of a front panel photo - and any information as to where or what it came from?

 

The style of the label looks 1960s or early 1970s prior to GEC taking over Marconi.

 

I'd guess based on very little info that it is a waveform monitor used to check modulation on an HF radio transmitter - this is effectively a simple oscilloscope.

 

Regards

 

Iain

 

You got all that from that label?! Remarkable...!

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Timbo

 

I have been involved in wireless since school days in the 1970s when radio shops, the small ads in "Practical Wireless", and radio club junk sales were still full of interesting stuff of this and earlier vintage. There isnt much to do with 1950s and 1960s radio that I havent seen (and havent wasted pocket money on :nut: )

 

Having seen the front panel it looks more useful than a waveform monitor - more like a combined test meter and low spec oscilloscope - I suspect a lot of technicians and Radio Amateurs would have gladly traded an AVO for it in the 1950s !

 

Regards

 

Iain

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Thank you for that,

 

Is it of any use or interest to anyone? As I got it for free I'd be happy to give it to a loving home (on the proviso that the home isn't eBay).

 

NELSON!!!

Edited by Caddy
It's a cricket thing - 111 posts.

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Caddy

 

I am probably close enough to pick it up (near Colchester) - I would be happy to try & get it working again. I could do with a replacement bench meter anyway even if only that part is ok - PM if you want to discuss further.

 

Regards

 

Iain

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Thanks Caddy for the invite to pick this up !

 

We got it home safe (with my arm a few mm longer after carrying it the length of Duxford) and it powered up and even gave a scope trace 2/3 of the screen wide with no smoke or sparks ! It is definitely the worse for component ageing but I think it will be successfully revived once I get a circuit diagram.

 

The bottom half is a Simple multimeter that works without mains power and reads about 12% low at the moment (so a good 1.5v battery reads 1.3v) - the top half is a single channel oscilloscope and still gives a trace and is even picking up electrical noise when one end of the Y input test lead is floating. The sweep is only 1/2 the width of the screen so I suspect there is an x amplifier problem though ;( Based on the components inside I would revise my age estimate earlier to late 1950s or early 1960s

 

Now to find a circuit and more of the 10H/260B insulated test leads - I think the strange type was chosen so a lead with the probe attached to a high voltage circuit under test was safe if the instrument end is loose on the bench unlike most modern ones!

 

A circuit needs to be found too ...

 

I will try and post the internal pics I took when I got home - expect an update in a few months!

 

Iain

73 de G0OZS

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Definately beyond my skillset to repair :wow:

 

It was good to meet you yesterday, and I hope that you get some use out of it.

Fascinating piece of ket though...

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Paul

 

Indeed an interesting item - the prehistoric anscestor of the modern scope/meter hybrids.

 

The low DC Volts reading I now understand - the set zero on the meter movement is loose and ineffective :( I have some other similar meters to use as an exchange so that ought not to delay me very much - I note in passing that the meter scale has a 1959 date so the instrument is no earlier than that. I may actually get the original movement fixed (a the father of a colleague at work was a watchmaker and has done similar repairs for me before).

 

The input test lead plugs are basically the same mechanically as a lot of small DC power plugs so I should be able to find something that fits & can be used with the outside left unconnected. That will be enough to get it going as a bench multimeter at least

 

Regards

 

Iain

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Timbo

 

I have been involved in wireless since school days in the 1970s when radio shops, the small ads in "Practical Wireless", and radio club junk sales were still full of interesting stuff of this and earlier vintage. There isnt much to do with 1950s and 1960s radio that I havent seen (and havent wasted pocket money on :nut: )

 

Having seen the front panel it looks more useful than a waveform monitor - more like a combined test meter and low spec oscilloscope - I suspect a lot of technicians and Radio Amateurs would have gladly traded an AVO for it in the 1950s !

 

Regards

 

Iain

it may be a phase shifter

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