New acquisition: Anritsu MS610B spectrum analyzer 10kHz-2GHz
Nice,
BUT 1V RMS is a LOT of input for a SA. It's +13 dBm or 20mW the MAX input for a 610B is 20 dBM (100mW see attached.) This is a bit close for comfort. If you manually switched the attenuation down you could blow the mixer. Add a 10dB attenuator to your shopping list and keep it on the SA until you have more experience. Fortunatly the 610B has good DC voltage resistance at 50V. Some SA mixers die with tiny amounts of DC.
YIKES! almost shit when i read that he was stuffing 1v rms into that poor thing.
my sop is to always keep 20 dB in front of an SA until sure that it is safe to go bareback. a blown mixer or toasted internal attenuator will ruin your day. i also have a 10W 60dB atten for use when messing with the output of transverters (mine are all 5W or less). others have suggested a dc block too.....not a bad idea.
a good SA is a thing of delicate beauty. be nice to it.
About that, and not having an SA myself nor knowing much about them.... I always wondered... since it's so easy to blow the front end, and since these instruments cost a tremendous amount of money... it always begged the obvious question : WHY the hell don't SA manufacturers protect their damn front-end in the first place ?!
Of course I am sure there is an obvious technical reason why that's not possible, and any SA owner knows about it.... but I don't. So please educate me if you have 30 seconds between two refills of your cup of tea/coke/coffee....
From what I see in voltmeters or even the RF front end of pre-scalers in multi GHz counters, the input is often protected by a couple of diodes that limit the voltage to a defined level. Then a resistor is put in series with the input, so as to limit the current going through the diodes, so as not to blow them, should they be solicited ...
Why can't that be done as well to protect against over voltage / too large signals on a SA ? or a variation o fit, or something else entirely that might be more suitable, I don't know.... SOMETHING !!!
Thanks.
Yours Truly.