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Some of the responses did not answer the question you asked. To answer the question below: modern signal generators, like the 8340, have a leveling loop to maintain a preset level. If you investigate

If it helps, this is the setup I typically use to level a microwave signal source and provide a low source VSWR. This provides levelling to the accuracy of the power meter and the source impedance is

Never mind my previous question - the picture you sent confirms the problem is most likely the attenuator.? I like the idea of subing a 10dB fixed for the switched attenuator followed by RECALL 8 and

One more question and then I'll "buzz off" and watch.? Did you see anything when you did RECALL 8. I read that you did not see anything when you did RECALL 9 If RECALL 8 worked and RECALL 9 did

These have a DC output, not RF so input impedance of the test equipment doesn't matter. They typically feed the vertical a scope or DC voltmeter . [email protected]> wrote:

The input VSWR of the 8473C is quite good up to about 18GHz, but above this a decent attenuator will have a lower VSWR.? So the attenuator acts to isolate the less than perfect VSWR of the sig gen

Crystal detectors are often used after a tuned circuit that drives a 50 ohm load. Without the pad, you can't [properly align the circuit by itself. [email protected]> wrote:

I had exactly the same problem. Bought a replacement attenuator on ebay and installed it ..Fairly simple procedure.? Now I have a very happy 8566B.

Bill, I suggest removing the fuse F4 and measure the resistance to ground at the terminals where the white / violet wires come to the board. With the fuse out the resistance to ground should be very

All, thanks for the replies. Does an RF signal gen such as say 8340B generally have poor source impedance? Has someone examined this before? I am wondering if the problem of mismatch and standing

Dave B, where can I find the terminology of "slugging" a control loop? First I've ever heard the term and I'm intrigued. Thanks, Dave W ________________________________ Sent: Monday, September 2, 2024

Q4 emitter is close to 0V anyway during use.? It is grounded by R11 0.27 Ohms, as the output current sense resistor.? Q4's base should never be +ve vs 0V by much more than a Volt or so, ever.? If

Bruce, There's clearly a fault here as there is no signal present to adjust. I've set out more complete info on this issue in the thread entitled "8566B Can't Calibrate" if you have the time to read

Q4 collector is around 16v still. C9 looks OK on the surface. R49 is a little hard to test but my old fluke says somewhere in the neighborhood of .02 to .04 ohm. No heat but signs of past heat, faded

Bill, What is the voltage at the collector of Q4? Also if you have a 10 A ammeter remove F4 and measure the current. I sounds like there is a short somewhere. Keep the fuse in the circuit to protect

After a few second warmup I get 1v at q4 emitter [email protected]> wrote:

Yep all purple/white disconnected on the left. Currently almost no voltage at output of q4 emitter, -0.02. It's also getting hot. Wonder if it's toast bc I lost my -2.5v since. [email protected]>

Bill. You are making progress! Now we have to find out where the -12.6 current is going. Especially since the driver is getting hot. It is funny that the current limiter is showing 0V. I think some

They almost certainly did specify a Schottky with an appropriate leakage spec. The problem wasn't the spec -- it was that the leakage increased beyond spec over time. More things can go wrong with the

That's what they say - but why go to? a 'regular' diode?? And go from 0.3 to 0.7 fwd drop. A better replacement would be a schottky with a low leakage spec. However, some power down circuits do get