I have a problem with the Attenuator from my HP8713B . i stay on the 20dB step instead of 0 db .How cant i tested it.I opened the attenuator and I see that the relais have two positions . You cant moved manual. is it possibel that it is mechanical problem . Piston dry ??
Yes, it is probably a mechanical problem. Sometimes dust gets in if you are using it in a dusty environment. A lot of these were sold to be used with trimming and tuning ceramic filters (using a grinder or dremmel tool) and the ceramic dust filled the air and was blown through the instrument.
You can try to cycle many times or try to open it up and force the position up and down. Usually, once you get it to move, it will be fine for a while. Are you the original owner of this, or did you buy it used. In the dot.com bust, a lot of these for filter companies were put on the second hand market.