The Heathkit IT-27 Transistor-Diode Checker

In this video we' take a look at a piece of classic Heathkit test equipment, the IT-27 Transistor-Diode Checker.

[@Melw44]

Just wanted to say thanks for these Heathkit videos. I have a bunch of Heathkit test gear that I picked up when I lived in silicon valley in California. Your videos are the first place I look for info when I want to know about what I have. Oh your book is on the way. 😁

[@tomcroley7084]

I have one I picked up at a hamfest in like new condition. It's a quick & handy little tester that takes up little bench space.

[@hestheMaster]

Fantastic demonstration of how the unit works Jeff.

[@manoffaith2501]

I wish Heathkit was still in business.

[@dougkubash8673]

I assembled a IT-27 back in the day.

[@SDsailor7]

Have the Heathkit IT- 18 transistor tester that I am trying to learn how to use it.

[@eugenetheodore2956]

Hi Jeff, I have a Heathkit IM-28 that I repaired & it worked fine. However, recently the r x 1 scale stopped working. Do you have any suggestions as to what might be the areas to check? Thank you, Gene.

[@jefftranter]

It if it only the RX1 range, it is likely a problem with a resistor or wiring around the range switch.

[@eugenetheodore2956]

@@jefftranter Well, it worked for a while & then not. What specific resistor would you check?

[@jefftranter]

@@eugenetheodore2956 It looks like the resistance ranges use resistors R24 through R30 on the range switch Wafer "C".

[@eugenetheodore2956]

@@jefftranter Thank you Jeff. I will check them.

[@uni-byte]

Selenium stack rectifiers have higher forward resistance, not lower.