Test Leads

[Vince]

Hi,
I am about to bring up, using Eric Hayes method, a Lowrey organ 6L6
mono amp. I have a Fluke 8012A and a PACO VTVM to monitor the process.
But I am concerned about the test leads I have.
Are the following adequate for the job?
1. The Fluke;
Both leads are home made with Banana type into the fluke (the only option) using probably 18 ga. teflon coated wire and press-the-button hooks at the test end.
2. The Paco:
The lead for this is a mutilated original for this unit(?). The connection at the meter is a screw type RCA(?). The test end has been
altered with an alligator clip on the center conductor and a male banana plug connected to the shield.
There also is a banana plug ground connection on the meter face just below the RCA screw connection.
Should I replace both these connectors with the press-the-button hooks
like the Fluke (if the fluke is adequate?
Thanks for your help, Vince

[erichayes]

hI Vince,

The connector on the PACO is known generically as an Amphenol microphone connector, even though Amphenol, to my knowledge, doesn't make them anymore. Switchcraft, on the other hand, does--model 2501F--and Mouser has them for $4.75 ea (cat #502-2501F).

If you look at the V-70 manual, you'll find that the probe had a switch to select DC volts or AC volts/ohms. I believe a 1 meg resistor was put in series with the probe and the meter in the DC volts position, but it might be some other value. In the AC volts/ohms position the probe was straight through. If you're going to be using the meter for all three types of measurement, it'll probably be easier just to make two probes, one with the resistor and one without. Regular single conductor microphone cable can be used for the probe lead, and a separate lead with a banana plug can be used as the return.

An alternative might be to check the surplus places like Alltronics, or the flea markets at Foothill or Laney and see if you can find a complete probe for a VTVM. They were pretty interchangeable; you might have to change the value of the series resistor to match your meter's requirements.