The PHILCO Phorum

Full Version: Modern signal generators
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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?
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.
Ron,

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