[Microwave] Ancient HP 626A

[Dave and Kathy Woodhall]

Hi everyone,

    I've been given a HP626A SHF signal generator that covers 10 GHz band. I
know it's not quite the latest technology but it will do as a test signal
source for some 3cm experiments I want to carry out!
 It had some minor faults that I've cleared but there is something I would
like help on.

1)    Circuit diagram or manual - I've got nothing so anything you may have
would help. Don't know how to operate it, never mind how to set it up.

2)    It stops oscillating at about 12.5 GHz, just before a microswitch
clicks in - when the switch is in it oscillates again till the frequency is
at the top of it's range. Possibly a set up of voltages?

3)    It has a thermal delay relay fitted that is faulty - does anyone know
where I can get an AMPERITE DELAY RELAY 115N030T.You would no doubt be
interested to know that I made a 30 second delay from a PIC micro as I
guessed that is what the 30 in the part number means! Bit of 2003 technology
never goes amiss, but I would like to put in the original part!

4)    Do you know how the pulse modulation is supposed to work. I can get it
to internal / external FM, CW, and modulate with a square wave, but don't
know how to make it pulse.

    Any help you can give - on or off list - would be appreciated.

    Thanks n 73 Dave ZS6BNT in sunny, but chilly (just going into winter)
Johannesburg South Africa.