WANTED: TENMA 72-465 Multifunction Counter Manual/Service Manual

[Shock]

Looking for the Tenma 72-465 Multifunction Counter Manual and Service Manual or Schematics. Preferably free, electronic version is fine, please let me know if you can assist or have one.

[Andy Watson]

Bears an uncanny resemblance to an Elenco F100

http://www.elenco.com/support/manuals

[Shock]

Looks close doesn't it, thanks for that. There is an extra button on the Tenma 72-465 "LF" thought that was a low pass filter at first but with in/out?

[Andy Watson]

You might have an updated version - the basic design seems to have been around for a long time. I have the F1000 - same case, including the L.F. in/out, but the trigger level is replaced by the prescalar input. Mine was bought as a Maplin "Gold" MF1000. These counter appear in several re-badged brands.

[Shock]

Do you know what the LF in/out is?

[Andy Watson]

No

I had always assumed that it was a low-frequency filter. I have just removed the case but it is not obvious how the switch is connected - only that it switches input to something else, or not. There is a 0.47uF capacitor in series with the input - I thought the switch might short it out to pass D.C. - but it doesn't beep-out and I can't see where the tracks go.

The circuit board is labelled HC-F1000lf, so it looks like Hung Chang were the actual manufacturers.

[Andy Watson]

By chance, whilst searching for something else, I found Maplin's original instruction book for the MF1000. All it says about the LF switch is:

Low pass filter
   approx  100kHz, - 3dB
   approx 150kHz, -3db at 20dB ATT

[Shock]

Here is a photo of the controls of a similar TENMA 72-465 to the one I have. Does the Maplin MF1000 have matching controls in that manual, namely LF instead of LPF? If so that might be the manual I need, possible to get a copy of it? Send me a PM if required.

[Andy Watson]

No, it's not looking good

I've attached a scan of the MF1000 operators manual. The front panel is exactly as it appears on page 4, plus the Maplin logo. I believe this is the same model but with the LF and Attn buttons swapped:
http://www.radiomuseum.org/r/hungchang_multifunction_counter_hc_2.html
The PCB in my counter bear the Hung Chang label HC-F1000-LF(6).

I've also attached the Elenco manual for the F1000 - it has the schematic for the model without the LF button. Aside from the LF button it appears to be very similar to my MF1000.

[Shock]

Thanks for that, seems almost comical it's labelled out/in, hopefully eventually someone will show up with the Tenma manual but in the meantime at least I have something to work with, cheers.

[Shock]

Necro bump

Still looking for the manual specifically an electronic copy of it.

[tonyalbus]

No, it's not looking good

I've attached a scan of the MF1000 operators manual. The front panel is exactly as it appears on page 4, plus the Maplin logo. I believe this is the same model but with the LF and Attn buttons swapped:
http://www.radiomuseum.org/r/hungchang_multifunction_counter_hc_2.html
The PCB in my counter bear the Hung Chang label HC-F1000-LF(6).

I've also attached the Elenco manual for the F1000 - it has the schematic for the model without the LF button. Aside from the LF button it appears to be very similar to my MF1000.

Thanks!

Helpful, looks like my Dynatek DFC1000 but pcb was labled HC-F1000LF too !