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Signal generator

 
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Signal generator

Post by crackle » Sun Feb 15, 2015 4:07 pm

Hi
Does anybody recognise this signal generator.
protect-path.cfm s.jpeg

thanks
Mike

 
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Joined: Tue May 01, 2012 11:23 am

Re: Signal generator

Post by turretslug » Sun Feb 15, 2015 4:39 pm

An Army use version of the (usually) RAF CT218, the main difference being a 35-85kHz band in place of the 18.3-30MHz band. I think some of these were also packaged in sealed transit cases and used by the Navy- presumably for the LF capability.

 
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Re: Signal generator

Post by crackle » Sun Feb 15, 2015 9:48 pm

Hi
Please can you confirm the manufacturer, is it Marconi Instruments.

Thanks
Mike

 
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Re: Signal generator

Post by turretslug » Sun Feb 15, 2015 10:39 pm

Hi Mike,

I believe it is a Marconi device, a large, heavy, complex and undoubtedly expensive bit of kit. A fairly good example of '50's defence over-engineering with its high resolution film scale tuning drive and quite complex saturable reactor FM modulator. I have heard it described as "a TF144H designed by a committee with someone else's cheque-book" :aaj Same size (i.e.6U) front panel as the TF144H but probably double the weight and chassis depth. Nonetheless, a good attenuator- something that sorts the real McCoy from the toys in the SG world. That looks like it has had the PSU mods (clue: voltage selector panel with two, rather than one primary change-over toggle for series/parallel 100/200V ranging) that adds a second mains transformer and additional stabilised HT/LT supplies.

How's your weight-training? :)

Colin

Edit- actually 8U high!

 
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Re: Signal generator

Post by crackle » Mon Feb 16, 2015 7:32 am

Hi Colin
Thanks, that's very useful.

Mike

 
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Joined: Tue May 01, 2012 11:23 am

Re: Signal generator

Post by turretslug » Mon Feb 16, 2015 12:04 pm

The hazy depths of my mind are clarifying a little on these behemoths, it's a long while since I used one... One serious caveat is that there is a two-gang tuning capacitor, one section serving the 6AM6 oscillator, the other the 6CH6 output amplifier. The output section's frame is live to HT, the clue being the fibre mounting washers and isolating coupling- this was to avoid signal currents having to circulate through large-value isolating capacitors. If I remember any more hazards, I'll post!

Does this thread mean that you've aquired one?

 
Posts: 2513
Joined: Sun Jun 10, 2012 7:23 pm
Location: Basildon

Re: Signal generator

Post by crackle » Tue Feb 17, 2015 3:55 pm

Hi Colin
Sorry, no I havent got one, I have been researching for the Radio Museum, one was proposed a little while ago, and there was no manufacturers name and little known on the internet.
Hopfully we have catalogued this correctly now for everyones benefit.

Thanks for your help.

Mike


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