The Heathkit IP-27 Low-Voltage Regulated Power Supply

[@tectalabyss]

Thank you for the interesting history and how it works videos.

[@ys1rs]

Bought one on eBay for my little boat anchor shop and provides the voltages correctly but the Amp limiting section is not working. I suspect the Zener diodes need replacement but are not found in my country. Was nice to see yours working well. Hope to fix mine soon. YS1RS

[@berkmanyt]

Nice job… AGAIN…Thank you walt

[@turboslag]

I have one of these in the UK, and the high voltage unit. The IP-27 has a fault though, which I must sort out. It was working when I bought it several years ago but I noticed some of the caps ran warm, so I replaced them with suitable modern components. After that, and despite carefully ensuring all connections were correct , it now won't produce any output. I suspect a change in circuit conditions has popped a transistor or two somewhere. The HV unit, which uses valves, works fine, they are highly sought after here, I was lucky to find mine at a reasonable price.

[@darrenclark6552]

pity you didn't provide the schematic.

[@jameseiden2340]

Found schematic and are very very blurry

[@berkmanyt]

Jeff, I have your book…the hwa-2036-3.a power supply is not listed ? ? ? I'm enjoying the book..it's renewed my interest in Heathkits. I have the Heath Commanche receiver and a HW-8 xcvr and power supply walt K2CXP

[@jefftranter]

I'm glad you are enjoying the book. The HWA-2036-3 power supply was designed to power the HW-2036 2M FM transceiver and similar equipment, so it was really part of the amateur radio product line and I didn't include it in the test equipment book.

[@berkmanyt]

Jeff Tranter Thanks Jeff

[@randomscience4k]

Hi Jeff, Nice video and fantastic explanation. Maybe its your sound that makes it very interesting to listen to!😀. I've a similar unit and it works fine. But something I noticed was that the two high watt resistors in the referenced voltage supply section gets pretty hot like the 2500 ohm 7W gets 308F and 1200ohm 2W gets like 191F if I set it to any voltage and leave it running at no load for like an hour or two. At first I thought the 250V CAN capacitor close to these resistors was bad since it was getting hot. But now after changing it with new capacitor after snipping of the old can capacitor and just leaving it for the negative lug also the cap gets pretty hot. Is it normal with your unit too? Or is something wrong in my unit?

[@jefftranter]

These resistors get hot on my unit, but not that hot. I just measured the 2500 Ohm resistor at 170F, so yours sound a little too hot. I would check the values of resistors in the circuit first and see if any of them are out of value.

[@goots2127]

I have a faulty IP-27 which outputs only around 10% of the power it should, and I found a hole in the bottom of the big capacitor (21C75JB33, 3,000MFD75WVDC) there is a hole between the red and brown wires. Is this whats wrong with it?

[@jefftranter]

That could certainly be the problem. It is common for electrolytic capacitors like that one to fail after many years. You can find copies of the Heathkit manual on-line and it has a troubleshooting section that may be helpful.

[@judges69]

Great video, thank you. I can not find knobs for mine, so frustrating

[@jameseiden2340]

eBay search for knobs or buy one from a guitar

[@fpvrcstuff]

I have one of these power supplies and it worked very well until I accidently shorted the leads, now it is very unstable and there is a clicking sound coming out of it ?

[@jefftranter]

I'd suspect one of the transistors as the most likely culprit. You can find copies of the manual on the Internet. That has a troubleshooting chart and a schematic with voltages listed that you could compare to your unit to try to diagnose the problem.

[@fpvrcstuff]

Thanks ,

[@jameseiden2340]

Cant find a schematic that isn’t blurry

[@judges69]

Hi, I want to do the update on my IT-17. Could you tell me if IN4758A 56v 1W is the correct zener diode or should I use IN5370BDL 56v 5W zener? You help would be greatly appreciated.

[@jefftranter]

I haven't tried it, but most people recommend using a 1N4007 diode. You may need to change a resistor value. See this discussion here: www.antiqueradios.com/forums/viewtopic.php?t=1182

[@judges69]

Thanks for the info.

[@natejobs7463]

How much is one of these worth?

[@jefftranterics]

Typically prices on eBay seem to be about US$40.

[@natejobs7463]

@@jefftranterics thanks