Heathkit IT-28 Capacitor Checker Repair plus demo Vintage Test gear how to

Recent addition to D-lab. This instrument needed some help but turned out great. Very handy for troubleshooting old amps. Heathkit was the best kit company back in the day.

[nichesound]

I have had three of these the one I use is spot on for values. Still have the coveted manual!!

[peteleoni]

I really enjoyed the info part which starts about 1/2 way in.

[nichesound]

I just checked 11 coupling caps in a 1974 Twin Reverb they checked out PERFECTLY! Those blue gumballz!! I lifted one end it is easier than replacing them willynilly!

[ThomasACarlos]

I am on a quest to build a simple Capacitor Leakage Tester, utilizing concepts I have seen in several DIY builds. We would start with a variable 240 vac transformer, being able to generate up to 400 vdc, monitored by an analog voltmeter to monitor the the source dc. The circuit would be simple, something like a limiting resistor, a place to connect the cap, routing this through a dc ammeter (maybe something with shunts for two scales). There would be a switch for "Leakage Test" and the other position would be "Discharge", going through a 47k limiting resistor. A second voltmeter would monitor the voltage across the cap (in the "Discharge" mode). The Heathkit eye is more like a Go, No/Go but it does not give you actual measurements. So my approach is to look at actual dc leakage current and then determining if it is acceptable (using tables I found on the net). It might be a tad more complex than this, but that is the idea. As always, thank you Terry for posting this video.

[tubeDude]

At 5:25 you didn't switch the left-switch to Electrolytic!

[zulumax]

5:49 When you're done, be careful not to touch the bare metal of the red lead when moving the lever from leakage to discharge. I always return the voltage to the lowest setting as an extra precaution as well. I also use a short set of 3 inch bananas to booted alligator clips (from my MESR-100 ESR meter) to get my fingers away from this high potential area. You would have thought they would have designed the high potential area away from the switch, but they did not. This is a great tool, but treat it with respect.

[mikeflosse]

Hi,
Related to the capacitor replacement topic, can you please let me know if it is a good idea to replace the two old original electrolytic 40µF 400V in series from my Heathkit IT-28 capacitor checker by three brand-new Solen PB-MKB 27µF 400V in series without balancing resistors? Budget is not an issue. Any help will be much appreciated.
Thank you very much in advance,

Mike

[TROTSKYSAN]

I have one of these heathkit IT-28 capacitor checher, i don't know if it's working, but the green light turns on, if anyone is interested, (it has no manual or box)

[mikeflosse]

Great job. Please, could you let me know the reference number for the new good-quality banana jacks that you used to replace the old ones? Thanks a lot in advance!

[SendARope]

I'm learning a lot from your videos about electronics. Thank you for making them.

[KCKEP]

The manual says that the tester can be used to determine transformer primary/secondary ratios .. but I haven’t tried it with mine yet. That could be pretty handy when evaluating salvaged transformers 😁

[adzbasslines]

I just managed to get my hands on one of these and fully restored it with quality parts and re-calibrated. Building amps, this piece of test gear is invaluable! The 1960's green painted version of the IT-11 are even more expensive to find than IT-28's. Some are in really bad shape. Finding them is getting harder these days. I heard the IT-28 discharge switch was spring loaded to return from leakage back to discharge if the user forgot to do so. Good idea. But my original IT-28 did not exhibit that to be so. I'll keep this thing forever!

[michaelswindal]

Thanks for the info. Just checked out mine, bought on ebay. The leakage test voltage only appears on the two highest settings; otherwise, no charging voltage appears on all lower ranges. How could this problem occur in rotary voltage control?

[aircooledcamper]

I have the same model and like that it can measure ESR of electrolytics as well as capacitance and leakage.It actually measures power factor on the little power factor knob, but all that indicates is the percent of the capacitive reactance that the equivalent series resistance is in ohms. Easy to calculate because it is always feeding 60 Hz to the capacitors being tested. For example, on a 40 uF capacitor, the reactance is about 66 ohms--so if the maximum eye opening occurs at the 5% mark of the power factor control knob, the ESR is just over 3.3 ohms. (5% of 66 ohms = 3.316 ohms).Pretty handy.

[Digital-Sparks]

I realize this is an older video, but I am in market for one of these older style Capacitance meters, and was wondering if you had a preferance as to which brand/model you liked most. I also repair old vintage radios, work on old boat anchors and tube type transceivers as a hobby.

[Mrchevyvan]

i also own a model IT 28 .however i like the nicer more colorful look of the previous model IT 11 instead.

[jonathanhorne]

I’d like to see a demonstration of the transformer checks. Ratio checks and any other transformer checks it can co

[Knifeguy]

Been trying to find one for months now. Apparently it is built with huge amounts of gold in it because everyone wants $200 and up for them. Absolutely ridiculous.

[johncunningham]

Interesting demonstration Terry; Your video has given me some idea's about testing procedures in general that would be invaluable. "Excellent"

[harrystevens]

In my opinion the best thing you can do with this fantastic piece of gear is test NEW caps the old ones are out anyway but who knows what your getting with new