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Modern signal generators - Printable Version

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Modern signal generators - Ron Ramirez - 05-24-2023

As most of you know, I invested in a Siglent SDG1032X function generator a few years ago after using an old Clough-Brengle for decades, then a B+K 4040 like John B's for a while.

Pros of the Siglent: Direct digital readout, no drifting.
Con of the Siglent: Output level too high for typical vintage radios, must be reduced to a usable level with the use of inline BNC attenuators. I am using three such attenuators, a 20 dB, another 20 dB, and a 14 dB to reduce the output signal by 54 dB. This has solved my "signal too strong" issue.

While I liked my B+K 4040, I did not like the fact that it, too, drifted in frequency while in use. Of course, the old 1930s Clough-Brengle drifted badly.

With the setup I have now, I am able to give my radios the best alignments possible. I recently had my RCA C15-3 console chassis out for a tuneup. The IF alignment was good already, but I was able to improve the RF alignment a good deal.

I'll ask this question - do the HP generators produce a low level signal usable in vintage receivers without overloading them?

RE: Need a digital sig gen - morzh - 05-24-2023

The sole problem with mine is, it is about 50 lbs or so, and moving it to the table and back poses the risk of back problems.

RE: Need a digital sig gen - BrendaAnnD - 05-25-2023

Ron,

The HP generators I had to leave behind would easily go below the thresholds of any radio I worked on (-134dB?)

RE: Need a digital sig gen - DaleHCook - 05-25-2023

morzh Wrote:The sole problem with mine is, it is about 50 lbs or so

50 lbs? That's a lightweight. My General Radio Type 805-C Standard Signal Generator weighs 117-1/2 lbs. I like to joke that if a tornado takes my house the workbench will still be there because of the 805-C holding it down.

RE: Need a digital sig gen - DaleHCook - 05-25-2023

Ron Ramirez Wrote:I am using three such attenuators, a 20 dB, another 20 dB, and a 14 dB to reduce the output signal by 54 dB.

Ron - The HP 355C (0-12dB in 1 dB steps) and 355D (0 to 120dB in 10dB steps) step attenuators are more elegant solutions. I have long owned both, largely for use with GR unit oscillators which lack step attenuators.


Ron Ramirez Wrote:... do the HP generators produce a low level signal usable in vintage receivers without overloading them?

They do - around less than 0.1 microvolt into 50 ohms is not unusual.