charlie@oakhill.UUCP (Charlie Thompson) (04/21/87)
I bought an HP 608D Signal Generator made by Hewlett Packard at a
hamfest last weekend. It has a calibrated output down to .1 microvolts.
Such low levels are useful for testing receiver sensitivities etc.
I had heard rumors that the generator *leaks* and that it will radiate
levels in excess of .1 uv making it somewhat less useful at low output
levels. I have two questions:
1) Does anybody out there have a manual for this beast that they
would be willing to xerox for me.
2) Does anybody have any experience with this known-to-be-popular
signal generator. Any suggestions on how to fix the radiation
*leakage* problem with some sort of modification.
Thanks in advance,
Charlie Thompson WB4HVD
Motorola Digital Signal Processor Operation
Austin, TX
(512)440-2939 w
(512)892-6161 hwarren@sniff.dec.com (warren sypteras) (04/22/87)
I don't have a manual (that I know of, I'll check tonight) but I thought you'd like to know that my HP doesn't leak. Warren
charlie@oakhill.UUCP (Charlie Thompson) (04/23/87)
In article <256@sniff.dec.com>, warren@sniff.dec.com (warren sypteras) writes: > I don't have a manual (that I know of, I'll check tonight) but I thought > you'd like to know that my HP doesn't leak. > > Warren I couldn't email this directly...forgive me. Warren, How did you determine that the HP608 you are using does not leak? Are you saying that no coax connected to the output AND with the output set at max attenuation (minimum output) that a nearby receiver like, say, a VHF scanner, doesn't pick up any signal when tuned to the same frequency as the generator? I hope the answer is yes since I can't use this beast if it leaks more than is useful for testing VHF receiver sensitivty. A good non-leaking generator for this purpose will have no detectable leakage by a nearby receiver tuned to the same freq. Thanks in advance, Charlie Thompson
dsi@unccvax.UUCP (DataSpan R+D) (04/23/87)
In article <870@oakhill.UUCP>, charlie@oakhill.UUCP (Charlie Thompson) writes: > I had heard rumors that the generator *leaks* and that it will radiate > levels in excess of .1 uv making it somewhat less useful at low output > levels. I have two questions: > > 2) Does anybody have any experience with this known-to-be-popular > signal generator. Any suggestions on how to fix the radiation > *leakage* problem with some sort of modification. Mine definitely does not leak. (It, however, is the military version which was made by several manufacturers). The secret to getting this thing not to leak is: 1) The cover to the tuned oscillator and IPA must be absolutely RF tight. This was before the days of "Sticky Fingers" and such. Mine has an aluminum plate which mates into a cast chassis, the plate has a groove machined into it, which must be filled with silver plated braided copper or such. My favourite is to get RG 174/U coax and pull the center conductor (including dielectric) out). 2) ALL . . . repeat . . . ALL OF THE SCREWS MUST BE PRESENT IN THE COVER. 3) The cable to the attenuator must be in good condition. The 608 and its various clones (which are identical) is a fine piece of equipment. I wish I'd a manual for mine, too. David Anthony DataSpan, Inc P.S. Does anyone know what XV3 is in a Tektronix 491 spectrum analyser?
jeffr@sri-spam.istc.sri.com (Jeff Rininger) (04/23/87)
In article <689@unccvax.UUCP> dsi@unccvax.UUCP (DataSpan R+D) writes: > The 608 and its various clones (which are identical) is a fine >piece of equipment. I wish I'd a manual for mine, too. Tucker Electronics sells manuals for the used equipment they sell, and they sell the 608D. Call Jan Malatia at 800-527-4642. Given their prices for used equipment, be prepared to pay a lot.
warren@sniff.dec.com (warren sypteras) (04/24/87)
I used the same method with the receiver. In my case I took a 220Mhz rec- eiver tuned to the gen output frequency with a 1/4 wave whip on it and moved around the gen. The gen, with it's output set at 1 uv and a dummy load plugged in didn't do anything to the receiver until I was within a few inches of it (the load that is). The receiver has a measured sens. of .08 uv. (to break squelch). What I've found consistantly with my gen is that the damn coax leaks far more then the gen does. I'm using a 5 ft. run of RG58u double shielded and the stuff still leaks more then the gen. I'm sorry, but I forgot to look for the manual. I'll do so tonight. Warren