I just finished up building a Super Probe kit I bought on Ebay and did the mods on an Eico 147 I had reconditioned with new caps and resistors. I checked the voltages on the tube following the volume control and found that the Eico 147 vs the 147A does not have that problem of tube saturation or the voltages dropping so adding the resistor and capacitor was not needed. They stayed rock solid. Now if you compare the schematics for the 147 and 147A, you see that the 147 uses 5 tubes vs the 147A 4 tubes plus that volume control goes to a pentode tube vs a triode tube. I am wondering if that difference of tube types is the reason for better stability? I'm guess Eico decided to cut some costs by redesigning the 147. Anyway thank you for the video showing us how to mod things.
Nice conversion of the EICO 147A. I don't have a Carson super probe yet and have not needed one. Nor do I have capabilities to make small PC boards. I do like the EICO signal tracer as a test tool. It also makes a good bench amplifier for testing audio device. Good informative video! btw, new subscriber!
The Eico was16 dollars at an estate sale, and it came with an isolation transformer. I did build that probe with through hole components on a perf board, that's why it is in a 3/4 inch copper pipe. But I got a 70 dollar microscope with lcd display for Christmas. I built the Ultra probe and amp with SMD components and once I got used to it, it wasn't that bad.
@@leonardpeters3266 $16 with an isolation transformer? WOW! What a find! I have a LCD microscope I bought for fixing hair wire coils. I guess I could pull it off with that. I'll have to give it a try. Anyway, loved the video Leonard! Thanks! Paul
Carlston design would be safer for a beginner as the probe and amp are all battery powered! My early employment back in the 60’s was valve power amplifiers full of hazards! As well as 240 volts Ac you had valve anodes 500+ volts Dc etc ! I had a few belters myself which taught me to put my left hand in my pocket when probing with my right hand! Health and safety didn’t have much clout then ! Now I use an isolation transformer and variac on any mains gear I work on now! Early colour tv’s were a death trap with 25kv on the crt anodes! I always grounded any crt as they can retain high charges for weeks! Hv capacitors you have to discharge before you touch anything! I worked about 50 years on electric/ electronic equipment and I am retired now on my 79 th year! 😊
Boy do I remember those TV's. They were really nasty, particularly the horizontal output tubes. If you ran across the plate of one of those it would cut you open and cauterize you at the same time.
I think it was Amazon. Here is a link to the new version. www.amazon.com/Converter-Universal-Isolated-Switching-Version/dp/B07SGQ6XXR/ref=sr_1_20?crid=UNJXFO1JL4NW&keywords=5v%2Bpower%2Bsupply%2Bpcb&qid=1687643960&sprefix=5v%2Bpower%2Bsupply%2Bpcb%2Caps%2C180&sr=8-20&th=1
Awesome, I picked a trunk load of stuff some time ago, this unit was in the pile. Now it's next on the list to bring back to life, new caps and resistors, bnc etc.
@@leonardpeters3266 Got around to opening it up, the unit was practically factory inside, pin 7 wasn't soldered on the middle tube, all the caps tested good, and resistors are in spec.
Great Video.. ! I have the same Eico signal Tracer and was considering doing something similar, but have not come up with any particular design ideas yet… Thank you for sharing.. I like the additional grid cap and bleed resistor added to the grid on the second stage.. I was wondering.. would it not be possible to somehow utilize the RF input for a high sensitivity input for the Carlson probe..? A different design approach, but wonder if that could work..?
Yes it would work. It would simply add another stage of amplification. I didn't because the gain of that Super Probe is already just crazy and I wanted to retain the RF probe for special issues. But it would work, just an awful lot of gain.
@@leonardpeters3266 I was thinking the same.. too much gain.. then I thought, maybe modify the Carson probe, by removing 1 gain stage..? Anyway.. that’s what’s great about this hobby.. there could be a different approach to everything…:)
That is a great question. I actually use the a ground lead from the EICO. It gives me allot more flexibility for placement and also frees up movement with the probe. It also quiets the probe down when working in a chassis. I liked the setup so much I used it on my Ultraprobe as well.
@@leonardpeters3266 - Ahh, ok. I’m in the early stages of building a stand alone Carlson Super Probe. I might copy you and just put a 4mm socket/binding post on my amp/speaker unit for a grounding lead. It seems to me that it would be neater for occasions where you can’t use the grounding lead and would otherwise be holding it in your hand as well as the probe.
@@alexwade9921 If you can skip to the Ultra Probe it would be well worth it. I have had incredible success with it. Here is a video demonstration of it ruclips.net/video/RIlTA8PcbpI/видео.html
Hello, informative video. I have two of the super probe boards etched, but never populated them, I wanted to knock out a couple of his cap testers (the one that shows outside foil and the one that shows micro amounts of leakage). Well now the ultra prone has been announced so I etched that board, populated it, have it in a case and all that’s left is wiring it up. Think you’ll plan on building the ultra probe? I’m doing the same thing, but with a Heathkit T-3 tracer which looks to be pretty much identical to your Eico.
I just finished up building a Super Probe kit I bought on Ebay and did the mods on an Eico 147 I had reconditioned with new caps and resistors. I checked the voltages on the tube following the volume control and found that the Eico 147 vs the 147A does not have that problem of tube saturation or the voltages dropping so adding the resistor and capacitor was not needed. They stayed rock solid. Now if you compare the schematics for the 147 and 147A, you see that the 147 uses 5 tubes vs the 147A 4 tubes plus that volume control goes to a pentode tube vs a triode tube. I am wondering if that difference of tube types is the reason for better stability? I'm guess Eico decided to cut some costs by redesigning the 147. Anyway thank you for the video showing us how to mod things.
Nice conversion of the EICO 147A. I don't have a Carson super probe yet and have not needed one. Nor do I have capabilities to make small PC boards. I do like the EICO signal tracer as a test tool. It also makes a good bench amplifier for testing audio device. Good informative video! btw, new subscriber!
The Eico was16 dollars at an estate sale, and it came with an isolation transformer. I did build that probe with through hole components on a perf board, that's why it is in a 3/4 inch copper pipe. But I got a 70 dollar microscope with lcd display for Christmas. I built the Ultra probe and amp with SMD components and once I got used to it, it wasn't that bad.
@@leonardpeters3266 $16 with an isolation transformer? WOW! What a find! I have a LCD microscope I bought for fixing hair wire coils. I guess I could pull it off with that. I'll have to give it a try. Anyway, loved the video Leonard! Thanks! Paul
@@ElectroRestore Good tweezers are also very helpful.
Carlston design would be safer for a beginner as the probe and amp are all battery powered! My early employment back in the 60’s was valve power amplifiers full of hazards! As well as 240 volts Ac you had valve anodes 500+ volts Dc etc ! I had a few belters myself which taught me to put my left hand in my pocket when probing with my right hand! Health and safety didn’t have much clout then ! Now I use an isolation transformer and variac on any mains gear I work on now! Early colour tv’s were a death trap with 25kv on the crt anodes! I always grounded any crt as they can retain high charges for weeks! Hv capacitors you have to discharge before you touch anything! I worked about 50 years on electric/ electronic equipment and I am retired now on my 79 th year! 😊
Boy do I remember those TV's. They were really nasty, particularly the horizontal output tubes. If you ran across the plate of one of those it would cut you open and cauterize you at the same time.
Sorry if this was asked before, but is the 5volt power supply linear, or SMPS
SMPS
Great Video Love your modifications. Where did you get the small 5 volt power supply its tiny.
I think it was Amazon. Here is a link to the new version. www.amazon.com/Converter-Universal-Isolated-Switching-Version/dp/B07SGQ6XXR/ref=sr_1_20?crid=UNJXFO1JL4NW&keywords=5v%2Bpower%2Bsupply%2Bpcb&qid=1687643960&sprefix=5v%2Bpower%2Bsupply%2Bpcb%2Caps%2C180&sr=8-20&th=1
Awesome, I picked a trunk load of stuff some time ago, this unit was in the pile. Now it's next on the list to bring back to life, new caps and resistors, bnc etc.
I think you're going to love it. It has really been a handy tool.
@@leonardpeters3266 Got around to opening it up, the unit was practically factory inside, pin 7 wasn't soldered on the middle tube, all the caps tested good, and resistors are in spec.
Great news, I think you will find it very useful
Great Video.. ! I have the same Eico signal Tracer and was considering doing something similar, but have not come up with any particular design ideas yet… Thank you for sharing.. I like the additional grid cap and bleed resistor added to the grid on the second stage.. I was wondering.. would it not be possible to somehow utilize the RF input for a high sensitivity input for the Carlson probe..? A different design approach, but wonder if that could work..?
Yes it would work. It would simply add another stage of amplification. I didn't because the gain of that Super Probe is already just crazy and I wanted to retain the RF probe for special issues. But it would work, just an awful lot of gain.
@@leonardpeters3266 I was thinking the same.. too much gain.. then I thought, maybe modify the Carson probe, by removing 1 gain stage..? Anyway.. that’s what’s great about this hobby.. there could be a different approach to everything…:)
@@esci8978 Absolutely, have at it and see what works best for you, wouldn't it be boring if we all thought the same way.
@@leonardpeters3266 Absolutely love what you did..! Cheers..!
Why don’t you have the grounding lead on the probe?
That is a great question. I actually use the a ground lead from the EICO. It gives me allot more flexibility for placement and also frees up movement with the probe. It also quiets the probe down when working in a chassis. I liked the setup so much I used it on my Ultraprobe as well.
@@leonardpeters3266 - Ahh, ok. I’m in the early stages of building a stand alone Carlson Super Probe. I might copy you and just put a 4mm socket/binding post on my amp/speaker unit for a grounding lead. It seems to me that it would be neater for occasions where you can’t use the grounding lead and would otherwise be holding it in your hand as well as the probe.
@@alexwade9921 If you can skip to the Ultra Probe it would be well worth it. I have had incredible success with it. Here is a video demonstration of it ruclips.net/video/RIlTA8PcbpI/видео.html
@@leonardpeters3266 - I haven’t heard of the Ultra Probe. Is that another Carlson design? Are there PCB’s etc available for it?
@@alexwade9921 Yes it is available on his patreon.
Hello, informative video. I have two of the super probe boards etched, but never populated them, I wanted to knock out a couple of his cap testers (the one that shows outside foil and the one that shows micro amounts of leakage). Well now the ultra prone has been announced so I etched that board, populated it, have it in a case and all that’s left is wiring it up. Think you’ll plan on building the ultra probe? I’m doing the same thing, but with a Heathkit T-3 tracer which looks to be pretty much identical to your Eico.
Yes I plan on building it this winter. Actually getting ready to order the parts right now. I intend on using the same input jack for that probe.
Exactly what i need for my collection of nice old broken radios that seem to propagate spontaneously! Thanks!
I'm sure your wife will be overjoyed. Ha