Tektronix 271x spectrum analyser info

"bob_e1947" wrote in news: snipped-for-privacy@74g2000cwt.googlegroups.com:

How does one program less stability into a high stability reference oscillator? I think you will find that your 2711 does not have a hi-stability ref osc(or it's hi-stab components) in it.

Hi Bob.. I know a little about these units.. Here goes.

1) The 2711 was not offered the 300Hz res BW mode. If you can find the PCB assembly (TEK still sells them for $1,200.00 ea!), simply plugging in the card and routing two coax cables will, supposedly, enable the hi res mode (hi res because the phaselock option is also enabled). This will give you a 300Hz res bw, phase lock and thus higher stability. The unit will still report that it is a 2711, however.

2) On the bottom of the power supply board you will find a group of 5 resistors (10 ohm) . Depending on the revision of the PCB they will be denoted as: Early pwr pcb rev: R880,R881,R882,R883,R884 Later pwr pcb rev: R871,R873,R874,R875,R883

These resistors will enable/disable certain analyzer features. Since you claim that you have opt 2 counter, one of these 5 resistors should be missing. You will need to play with these to see what features are available. In some cases, without additional hardware, the analyzer feature may be useless. You will have to see. I will bet, however, that you can make the unit report itself as a 2712. But, again, without the 300Hz filter board you will not get the standard 2712 features.

3) One other option, the Video Monitor mode, can be enabled by shorting a spot where a 10 ohm resistor would go. Look at the schematic for the sweep board and locate R451. This will show a 10 ohm resistor at this location. You will find on the PCB that that resistor is absent. If you have a 10 ohm resistor, solder it (or a piece of wire) across the solder pads and you are in business.

4) The RS232 board is another TEK acquisition that will be EXPENSIVE. If you can find either the RS232 or the GPIB, then the extra NVM will come as a bonus. You cannot install both the RS232 and GPIB, no room.

5) There is no need to change the firmware, it is all there.

By the way, did you get any control software with your unit? I would guess not since you claim you are looking for an RS232 board. Maybe you got the GPIB board instead? Tek offered a PC software application for controlling the 2711/12 analyzers (Tek # S26UT10). If you received this, may I have a copy?

Well take care and good luck.. Jim

See above...and additional posts. Cheers...Bob

Thanks for the info Jim, this is the sort of stuff I am after.

Unfortunately I don't have either Opt03-RS232 or Opt08-GPIB and don' t have a copy of the software either.

BTW, I did find some nifty software the other day for printing from most older test equipment which used Epson or HP plotter format.

Check it out here

Cheers...Bob