Analog Meter:  Triplett 850 - Page 1
Forum section: electronics / beginners

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: December 02, 2023, 07:12:02 pm
content: I was looking to buy one of these analog and I really like the design of this one. Was this Triplett 850 a  regarded meter? Seller is asking $35 + $20 s/h.Thank you,- Wil

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: December 02, 2023, 07:58:34 pm
content: It is a Vacuum Tube Voltmeter really the same as the RCA SeniorAbout $10 at Hamfest. They are good but usually need work.It does have the leads which is important.https://www.radiomuseum.org/r/triplett_model_850.html

author: TimFox
author_rank: Super Contributor
timestamp: December 02, 2023, 08:56:46 pm
content: Obviously, you need to replace the cables that have worn out.Note that in the DC Voltage probe, there is a 1 megohm resistor near the probe point to isolate the capacitance of the coax cable from the point being probed.You should be able to salvage the probe connectors when replacing the cables.I'm not sure where the unit switches out that resistor when measuring resistance: many similar meters have a separate unshielded cable without series resistor for ohms.The probe resistor is very important when probing DC voltages on vacuum tubes in RF circuits.

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: December 02, 2023, 09:07:58 pm
content: Quote from: Wallace Gasiewicz on December 02, 2023, 07:58:34 pmAre you saying I should just wait for a Hamfest to roll around? I guess there isn't a guarantee that one will even be available. Looks like I'll need to Google "hamfests".- Wil

author: CaptDon
author_rank: Super Contributor
timestamp: December 03, 2023, 12:48:42 am
content: The Eico VTVM's had the switch housed right inside the probe. AC/OHMS was one position DC was the other position. Most were like that, the Heathkits and so forth. One of the coolest VTVM's that I remember was made by Hickock and had a meter about a foot square! It was a beast for size but didn't weigh very much. You could read the meter from across the workroom.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 03, 2023, 01:19:55 am
content: Quite a beautiful nostalgic design.I also have an analog meter (Handykit MK-2010BZ) and I like it for long time monitoring voltages or currents. There has not been a battery in it for 15 years because it does not need oneI also like the use of two knobs, one for function and the other for range. Mine has only a single 20 position knob, and because of that it has to "skip" a bunch of ranges.But the scale on your meter is quite silly. It has:2 scales that meas measure up to 5 or 50.2 scales that meas measure up to 1.5 or 15.2 scales that meas measure up to 14 or 140.2 scales that meas measure up to 4 or 40.It's a bit of a shame for the red scales. Those could easily have been mapped to an extra position for the function switch.It also does not have a mirror scale, but I find those overrated. Just remember there is a parallax thing, and look at the meter sort of perpendicular from its front panel.A good test for the meter itself is to first hold it in a position that needle points straight upward, then note down it's position. then rotate it to point the needle straight down and note it's position again. If there is a deviation you can balance the meter with little drops of nail polish or glue. Repeat the procedure for left / right.But overall, I would not pay USD35 for such a meter, and the shipping sours the deal even more.I would buy it for around USD10, but certainly not more then EUD20 (Inclusive shipping).