Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: Bluebark on August 24, 2025, 04:17:05 pm
-
I have come to the conclusion that I need to step up my game to work reliably in this world. But funds are tight now a days so...
How reliable do you find used meters on ebay/FB/Local or some other type of secondary market?
This one seems to be available and close. It's a Wavetek. I've included the spec sheet and it looks to hit all the main point but would really appreciate a qualified opinion.
-
for typical repairs n builds any meter that can reliably read Volts n ohms works. needs to be able to read 600VDC and at least 300VAC
once you have a meter spend quality time reading the manual, measuring known good voltages; car battery, 1.5VDC batteries, house AC, wall-wart voltages...
you need a good signal-source for signal path chasing, from my understanding there are good APP's for smartphones that generate a tone, can measure frequencies, I have a flip-phone so I use my scope n sig-gen
I consider a scope essential but you can get by with a signal source and a listening amp for signal path work.
most important tool you need is understanding! If you don't understand what something should be, all the test equipment won't matter since you have no basis for what your equipment is telling you.
-
During the turn of the century I was dong a lot of computer mods. Water/phase-change cooling, PWM fan systems, lighting....crap like that. I bought a mutli-voltage breadboard and learned to build small circuits, do limited troubleshooting. But it was all just a learning platform. No real signal chasing and High Voltages!!
I am currently using a el cheapo cen-tech DM and a chinese auto range. The cen-tech is reliable for big voltages but I question the small readings. The auto seems ok but is slow as hell, refresh rate. Someone posted a vid with a guy going over all the point of choosing a good meter. But I no longer make the kind of money to drop $400+ on a meter.
So I did my universe thing and this HD160 popped up on the secondary market. It looks close to having all the important things to have in a good meter. I was just wondering about peoples experience with purchases in the secondary market and if the meter was worth getting.
As for a signal source, a boating buddy gave me this when I was doing mods. Not really familiar with scopes. Got to get probes for it. Question...are these probes universal or do they require manufacture specific probes?
(https://i.imgur.com/7i83wQo.jpeg)
(https://i.imgur.com/5vDwCQZ.jpeg)
-
universal but, check the ratings, I've seem some that can only handle 150VAC. you want 2 probes, a 1X and a 10X, if you find lost money in the couch a 100X is nice but you can cheap-out with a homemade using a string of 1M R's to form a voltage divider.
-
Thank you sir. I'm going ask if the guy will take a hundred for that HD160. Going to hurt but better than risking my health.
thanks again
-
If I was going to spend $100 on a meter, I'd get the Klein MM720 for $90. I have one and trust it as much as my Fluke 85V.
https://www.amazon.com/Multimeter-Auto-Ranging-Resistance-Klein-Tools/dp/B0B57PDQJC/
-
Weeell, I don't really want spend a c note on a meter. Just seems like a good deal...HD160 sells for around 400 new.
I'll take a look...thank you.
-
Although I love my Fluke, I have several $35 DMMs which are almost as accurate. Almost, as in no meaningful differences for guitar amp work. If a Benjamin is scarce, go with a cheap Chinese meter.
-
After a looong argument...with myself, I broke down and sold some silver to help fund this tube amp thing and replace all the money I've dropped so far. So if the guy with the HD160 refuses my offer, I will probably get the Klein that SEL49 recommended.
I have chinese auto but refresh and continuity are slow and I no longer have surgeon's hands...
-
If I was going to spend $100 on a meter, I'd get the Klein MM720 for $90. I have one and trust it as much as my Fluke 85V.
Ask and the universe provides. While looking for that HD160 on marketplace, I saw a new 720. Offered him $50 and now it's mine.
Thanks for the advice.
-
universal but, check the ratings, I've seem some that can only handle 150VAC. you want 2 probes, a 1X and a 10X, if you find lost money in the couch a 100X is nice but you can cheap-out with a homemade using a string of 1M R's to form a voltage divider.
Any recommendations? A quick look on amazon and the kits go from $25 to $2,800 for HV differential probe kits. This kit is $25 but the low price gets me wondering. What do you think?
Bandwidth: DC-200MHz
Attenuation ratio: 1X/10X
Rising time ＜1.75ns
Input resistance: 1MΩ/10MΩ ±2%
Input capacitance: 1X:70pF-120pF, 10X:13pF-17pF
Compensating range: 10pF-35pF
System bandwidth 1X:DC-6MHz 10X: DC-200MHZ
Input voltage 1X:<300VDC + AC Vp-p 10X:<600VDC+ AC Vp-p
https://www.amazon.com/Proster-200Mhz-Oscilloscope-Grabber-Adjust/dp/B089YBMB9K/
-
more than adequate for tubes amps, anything audio, I wouldn't use them
of for satellite TX/RX but... :icon_biggrin: