Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 0

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 1

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 2

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 3

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 4

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 5

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 6

Vintage Military RF Signal Generator, AN/URM25D, US $2300 – Picture 7

Vintage Military Rf Signal Generator, An/urm25d

US $2300

Elgin, Illinois, United States
Mar 1st

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Up for auction is an AN/URM25D signal generator. The generator will provide a modulated or unmodulated signal over the range of 10 KHz to 50 MHz which can be varied between 0.1uV to 0.1V. The signal can be modulated at 400 or 1000 Hz. It also has and audio output at 400 and 1000 Hz which can be varied between 0-3V. It has a 1 MHz crystal controlled oscillator for calibration and there is an output for this but I am not sure it makes it to the output connector. The level control pot seems to be dirty or worn and at RF frequencies may not be working right which seems to be affecting this feature. The generator is still relatively accurate. I compared its output signal to an HP8640’s output ( To be honest I can not make any guarantee as to the accuracy and/or calibration of the 8640 and HP141S spectrum analyzer) and it was essentially identical at 1MHz as well as 50MHz in both frequency and signal level. See the attached photos. The first photo is the 8640’s signal (50MHz at 1mV) and the second is the 25D’s signal. Also included are a 5:1 and 10:1 fixed attenuator, an impedance adaptor, a dummy antenna and a couple test lead adaptors. I have also included a copy of the user/repair manual. The housing is typical of a piece of equipment of this vintage and has some dents and paint scuffs and scratches. It is not real pretty. Fortunately this has no effect on performance. The generator has performed well for me for a number of years until I replaced it with the 8640, however as with all vintage electronic equipment I can not make any guarantee other than it worked when it left my house. Also it is quite heavy, approximately 35 pounds so shipping will not be cheap. Local pickup is an option.