What do you think about the Tek TM-503?

The TM503 is a mainframe. It's major limitations are about 15W/hole power availability and difficulties getting that heat out. The plug-in performance is SEVERELY constrained by these limitations. For example, the PG502 runs on ~15W. At the time, the closest competitor from HP used 250W. Most of the design effort for TM500 stuff went into squeezing 100lbs. into a 5lb. sack, not into performance.

If you need to assemble 3 instruments into a semi-portable test set, the TM-500 system can be very handy...as long as you can live with the specs on the various products. Some of them are quite good, others are crap.

If you buy a used mainframe, check it out before you plug in any instruments. There's a small discussion of why here:

mike

I've got a 504 with a counter, DMM, and two function generators. It works nicely enough for me, although the power transformer hums a bit much at times. Harvey

Watson A.Name - "Watt Sun, Dark Remover" wrote in news: snipped-for-privacy@news.dslextreme.com:

TM503 is just a mainframe with 3 slots for adding TM500 series plug-ins,it contains several unregulated +/- supplies. The instruments are a DM502A 3 1/2 digit DMM (Useable,but not great) DC503A Counter-timer(not bad,not great) and a PS503A power supply;2 0-20V 0.5A(1A in hi-power MF)tracking adjustable supplies and a +5V regulated fixed supply. You get more current available if you use a TM504 or TM506 mainframe,they have the "hi-power" slot.

In article , snipped-for-privacy@abuse.gov mentioned...

Thanks for all the info, everyone. I have a much better idea of what and why these are out there.

Watson A.Name - "Watt Sun, Dark Remover" wrote in news: snipped-for-privacy@news.dslextreme.com:

I forgot to mention that there's the option of -dedicating- or customizing a TM50x slot to a particular plug-in,and for using the rear interface connectors.There's a plastic clip that goes over the interface connector to block PIs that don't match the one you selected.That PI will have a narrow notch in it's PCB at the edge connector,the notch placement varies for each model PI.The Rear interface is more commonly used on the TM506,though,but can be used to pass signals from one PI to another without external cables or using the front panel connectors.There was a manual-type book listing all the TM500 PIs and their rear interface connections.

The clips often were damaged when someone tried to insert a wrong PI into the dedicated slot.