With the 8902A.
I was able to get good readings all the way to 27 Ghz, but after that the next check was at 39 GHz. Well this was where my problems began.
The 8902A would tune to the 39 GHz frequency, but would do nothing else.
If I understand correctly the 8902A will perform to 42 Ghz.
So please help
Oh yeah I was using a mixer and following the diretions from the book, but it still wouldn't work properly.
Someone please point out to me what I was doing wrong.............
Well, the 8902 is a work horse, but showing it's age, like the 3458 according to some on this website. Anyway TRF measurements at this frequency are touchy with the 8902, I assume you are using opt 020 and using the applicable special functions? Are all the Time bases synched up, sometimes the 8902 must be optimized as opposed to just calibrated.Sometimes you must sacrifice a virgen to the gods.....and sometimes the unit under test might just be bad...very bad...
Quote from: Colt45 on 12-15-2006 -- 22:06:08
Well, the 8902 is a work horse, but showing it's age, like the 3458 according to some on this website. Anyway TRF measurements at this frequency are touchy with the 8902, I assume you are using opt 020 and using the applicable special functions? Are all the Time bases synched up, sometimes the 8902 must be optimized as opposed to just calibrated.Sometimes you must sacrifice a virgen to the gods.....and sometimes the unit under test might just be bad...very bad...
Some more detail please................sacrafices.....yep.
The UUT was good, it was checked on a spec an.
I never had problems with the 8902 unless it was bad. As long as you are using 2.4mm cables from your LO and UUT above 26.5Ghz and a 40Ghz mixer it should work. Of course you need to make sure that your LO is pumping out atleast +10 dBm. Did you verify your 40Ghz mixer? You could check your 2.4mm cables on a VNA at 39Ghz to verify that it isn't your cables. You can use the 8902 all the way up to 50Ghz if you want to. It sounds to me like you are using 3.5mm cables. You cannot use 3.5mm cables above 26.5Ghz and the downconverter has a max of 26.5Ghz. You need an external mixer rated to 40 or 50Ghz and a set of 2.4mm cables. I recommend that you use a 50Mhz offset on your LO. PM me and I can help you out. I have done microwave for many years with the 8902. I am not real sure what Colt45 is talking about but you do need your timebases tied together and opt.50. If you are using the 8902MS system then it should work. Can you tell us exactly what your setup is? If the 8902 was working @ 27Ghz then it's not the 8902. It has to be the setup ie..cables, mixer, LO RF output and Frequency offset. Did you manually lock the Freq. with the 8902 @ Freq. offset? Also the 8902 will only take a max of 1300Mhz. That's why your offset Freq. is what you have to lock your 8902 with.
Okay the chicken guy got me, it;s opt 50 that you need. One important thing is to double check your sensor, run it without the uut directly into your 8902/sensor head at each frequency tested.If the sensor fails you know what you gotta do.
You don't need your sensor when doing Tuned RF Level. You just need your UUT and a LO. Connect them to your mixer. Connect your IF out directly to your 8902A input. Use a 50Mhz frequency offset on your LO and +10dBm ( 38,950,000hz @+10dBm ). manually tune your 8902A to 50Mhz. Then go to TRFL and reference. Use special function to put in actual dBm @ 0. Then start dropping your attenuator by 10dBm. This is all you have to do. :-)