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Old 9th Dec 2017, 6:52 pm   #6
David G4EBT
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Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,766
Default Re: Advance E2 Signal Generator repair

Quote:
Originally Posted by thejazzageuk View Post
Thanks Techman.

Not sure if I am testing it correctly though. I have connected a 75ohm resistor across the 'ATTEN RF' socket and connected a scope across the resistor. With all the settings set to minimum I slowly increased them but see no reading on the scope.The scope I have is a basic PC version (Hantek 6022BE). I've not connected the full RF socket yet- thought it best to go slowly.
As Graham says, just connect it directly to your scope.

When you say 'you haven't connected the full output yet - thought it best to go slowly', if you look at the manual you'll see that the full output is just 1V p-p. The attenuated output ranges from 1µV to 100mV so you won't do any harm with it. Indeed, you'll need to set the scope to less than 1V per division to see a trace. The 400Hz AF output ranges from 0 - 50Volts, so is of much higher in amplitude. With the internal modulation switched off, you should get a nice clean sine wave, then a modulated sine wave with the internal mod switched on, and will see the variation in modulation depth when you turn up that control.

Really well made generators - their outward appearance is often scruffy and pitted with rust, but internally, unless 'got at' will look as good as when it left the factory, as can be seen in the pics below, of Type E Model 1, similar to the E2 but only goes up to 60MHz rather than 100MHz, which is no hardship). Very well screened - can be quite a task to open the case as it's such a snug fit. Easy to work on if any restoration is called for, and all the key voltages are listed in the manual. Because test gear tends to be little used, it's unlikely that the valves will be on their way out.

There are just two tubular paper caps that might benefit from being changed, (.05µF 350V - use .047µF), and two 16µF separate tubular electrolytics (reservoir & smoothing caps). All easy to get at. The two filter caps in the mains input should also be upgraded to modern 'Y' rated caps, but best to check the actual values of the caps - they're stated on the circuit as .0005µF, (500pF), which sounds like at least one decimal place too many, but I may be quite wrong on that.

You might actually discover that when you familiarise yourself with the controls and the scope, that it's working fine. I don't have the one in the pics any more, but when I did have it, the calibration was spot on when checked on my frequency counter, with no drift after being left on for several hours. They were built for professional use, which is abundantly evident from the solid construction and screening.

(The output sockets are sometimes modified to BNC to be more compatible with modern test leads).

Best of luck with it.
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