Another PCB Release! Build a Dirt Cheap Active Probe Or Buffer For Your Test Equipment Or Receiver.
Added 2019-01-16 14:10:03 +0000 UTCHere's an essential tool for aligning and repairing transceivers, receivers, frequency standards and so on. Build this into a probe, or this can even be installed inside receivers for adding an external frequency counter. Give your old short wave receiver, communications receiver, or broadcast band radio the ability to have an external frequency read out.... Or just use it to align them!
Here is a link to the list of video's here on Patreon, NEW LIST of Videos: https://www.patreon.com/posts/8239565
This is video #61, include this when requesting attachments.
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Comments
Thank you Mr. Carlson
LoSaYa
2022-10-17 20:00:31 +0000 UTCWhy the through-hole transistors? Without the schematic to input, we have to enter the entire diagram to get it to use sot-23 parts.
Dan Barker
2021-04-04 12:52:24 +0000 UTCIs a parts list located anywhere for this?
Andrew Curlik
2020-04-12 14:33:38 +0000 UTCHi Garry. The 49.9 (50) Ohm resistor is to help minimize RF reflection. Without the resistor, the waveform distortion at some frequencies will appear to trick the frequency counter into thinking that it's seeing another frequency.
Mr Carlson's Lab
2019-12-02 04:42:56 +0000 UTCWhat is the purpose of the 49.9 ohm resistor
Garry Norbury
2019-12-02 00:35:56 +0000 UTCenclosure: https://www.ebay.com/itm/5pcs-Extruded-PCB-Aluminum-Box-Black-Enclosure-Electronic-Project-DIY-50-25-25mm/372496860559?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
Emerald Pawn
2019-11-03 18:34:28 +0000 UTCI use these little aluminum enclosures and this pcb fits perfectly. The bnc mounts screw on each end.
Emerald Pawn
2019-11-03 18:33:54 +0000 UTCHey Mr. Carlson, RE: PCB Files Release: The "Special" Capacitor Tester!" Is there a parts list for this project including the "size #'s" for the components. Shipping costs are an issue for me and I don't want to pay for shipping more than once. Thanks.
joram kalfa
2019-11-01 18:12:20 +0000 UTCHi Alan. If you used an op-amp that exceeds the frequency range needed, you should be fine. Use appropriate protection on the input.
Mr Carlson's Lab
2019-03-17 12:14:24 +0000 UTCWhat's the advantage of this circuit over an opamp buffer? I'm assuming it's the diminished output you were saying is desirable. However, I'm not sure why diminishing the output to your scope is desirable. I'm creeping into RF circuits now that I have an old Magnavox console table to repair.
Alan Jurisich
2019-02-20 20:20:42 +0000 UTCOk, I just finished making my PCB. Toner transfer method worked great for this. Could you Paul, please always include a part list pdf? Thank you!
S.M.D.
2019-02-09 17:22:32 +0000 UTCI realise now that the 2n7000 is a moss fet
Garry Norbury
2019-02-03 11:26:34 +0000 UTCI noticed that the 2N5486 is obsolete in the UK,the alternative is the J106 I know you said most any jfet will work ,I tried the 2N700 and that will not work I have not got any alternatives to try ,so I will have to order some J106 ,it would be helpful if when you do a project you could make sure you can get the parts and they are not obsolete or put a couple of alternatives that you know will work Thanks
Garry Norbury
2019-02-03 09:34:14 +0000 UTCwould this work on audio circuits
God 420
2019-01-27 02:27:00 +0000 UTCNow I understand, Thanks you!
Roman Charak
2019-01-26 15:13:23 +0000 UTCYou're very welcome Gary!
Mr Carlson's Lab
2019-01-26 14:08:15 +0000 UTCThanks for your input Steven.
Mr Carlson's Lab
2019-01-26 14:04:04 +0000 UTCHi Roman. If you use 50 Ohm coax, you should have that resistor in series with the center conductor. If you use 75 Ohm coax, you can use a 75 Ohm resistor in place of the 49.9 Ohm resistor.
Mr Carlson's Lab
2019-01-26 14:03:42 +0000 UTCHello Mr Carlson. Is 49.9 ohms a critical value for the output of the Buffer Circuit? Also, would Vector Monitors or Vector scopes be suitable for a Curve Tracer project? I see a few for sale in a local Electronics Surplus/Salvage Store.
Roman Charak
2019-01-25 17:40:50 +0000 UTCHi Mr. Carlson. Love your videos. I've been out of electronic circuits since the days before surface mount devices became commonplace. Could you consider a video explaining the different sizes and nomenclatures of the SMD numbering you were using throughout this video?
Steven Emert
2019-01-25 12:11:24 +0000 UTCWow, this is what I have been waiting for! Simple, effective and oh so useful, thanks Paul for all you do!
Gary Bevis
2019-01-23 19:17:50 +0000 UTCYou're welcome Roman.
Mr Carlson's Lab
2019-01-23 02:39:15 +0000 UTCOkay! I only had to re-watch your video 20 times to glean all the information I wanted. Wow, you create such comprehensive videos . Thank you.
Roman Charak
2019-01-22 17:50:30 +0000 UTCHello Mr. Carlson - super neat circuit! Are all the capacitors ceramic capacitors?
Roman Charak
2019-01-22 15:04:57 +0000 UTCYou're welcome Scott!
Mr Carlson's Lab
2019-01-19 19:13:41 +0000 UTCI've been needing one of these devices! ๐ค
Adam
2019-01-19 08:19:39 +0000 UTCThank you, Paul. This is a great, useful device that you explain very well! I will be building mine soon.
Scott Boerner
2019-01-19 02:36:45 +0000 UTCOf course I loved your elegant board vs my thumbs only board. Actually, I am considering yours, not mine, for the SX-71 because the chassis and the above chassis are more crowded. The SX-71 is dual IF with the first IF driven by a separate 6C4 oscillator for the first 455 Khz IF. The cathode is direct connected to ground, so the only options are grid or plate. American Electronic Specialty Products uses a tube shield as a pickup and that may be what i have to do.
Albert G.
2019-01-17 22:01:10 +0000 UTCAnother nice one, and timely too! I'm almost ready to set up my TS-830s for actual use. This circuit should help me hook up an SDR to the old tube rig without destroying my equipment. Thank for the circuit files and video!
kmpres
2019-01-17 12:07:54 +0000 UTCYou're welcome Don!
Mr Carlson's Lab
2019-01-17 08:57:06 +0000 UTCYou're welcome Yannick!
Mr Carlson's Lab
2019-01-17 08:56:18 +0000 UTCGlad to keep you busy Nick!
Mr Carlson's Lab
2019-01-17 08:55:59 +0000 UTCYou're welcome Tom!
Mr Carlson's Lab
2019-01-17 08:55:26 +0000 UTCGlad you enjoyed Roy!
Mr Carlson's Lab
2019-01-17 08:54:33 +0000 UTCYou're welcome Michael!
Mr Carlson's Lab
2019-01-17 08:54:09 +0000 UTCThe transistors are not surface mount so you can add sockets to the board and use what transistors you have on hand.
Mr Carlson's Lab
2019-01-17 08:53:46 +0000 UTCTransistors to a few hundred MHz, and anywhere between will be fine. The board was designed to put in a communications receiver that operates to 30MHz.
Mr Carlson's Lab
2019-01-17 08:51:58 +0000 UTCGlad to share Ralf!
Mr Carlson's Lab
2019-01-17 08:49:32 +0000 UTCYou're welcome Buddy!
Mr Carlson's Lab
2019-01-17 08:49:14 +0000 UTCUnless you are dealing with very high frequencies, squared off traces are just fine. You will notice that most surface mount components are square.
Mr Carlson's Lab
2019-01-17 08:48:59 +0000 UTCGreat project Paul! Due to next to no room, I am planning to build an all SMD version to tap the first IF of my IC-756 Pro III to drive a SDR for a pan adapter. I was planning on looking into a buffer, but suddenly it shows up! Thanks!
Tom Thornton
2019-01-17 08:32:01 +0000 UTCThanks for another great designed circuit.
Escabusa Roy
2019-01-17 05:10:24 +0000 UTCWOW Paul! You did it again! Fantastic circuit design. I will be making a few of these! Thanks so much for sharing!
Michael, KE4EST
2019-01-17 02:30:53 +0000 UTCOutstanding! Just what I need to pick the IF off of my Yaesu FTDX-1200 for a panadapter. And sorry if this is a noob question but why are all the components surface mount except for the transistors?
Mitchell Smith
2019-01-16 23:44:04 +0000 UTCHi Paul, I will definitely be building one of these. Thanks for doing the design and sharing. What would you expect the upper frequency limit be for the transistors used in this design?
Stanley Chytla
2019-01-16 23:42:48 +0000 UTCVery useful circuit which comes at the right time! I'll try an active probe version with a different JFET I have on hand. Many thanks Paul, for sharing all your goodies!
Reb Elba
2019-01-16 22:36:10 +0000 UTCOh yeas! Just in time for a few projects I am working on, This will come in very handy. As always thanks Paul for doing the leg work on this.
The Radio Shop
2019-01-16 21:20:57 +0000 UTCI see that you have 90 degrees angles on the traces. Our Australian friend EEVblog always comments that these should be avoided. What is your position on this?
Robert St-Laurent
2019-01-16 21:12:27 +0000 UTCYet another great project thank you Paul for Keeping me busy while looking for a job.
Nick Vacalo
2019-01-16 20:35:36 +0000 UTCThank you Paul, i think this device will be a great addon at the output to my 10 mhz gpsdo. Instead of finishing with an 7404 i'll buf the output with :) Yeah a nice little project to built. Thank you again!
Yannick Turcotte
2019-01-16 20:24:49 +0000 UTCI am excited to get at all the projects. As you know I,m on my first one but when its functional on to the next. Thank You.
Donald (Don) Stewart
2019-01-16 20:03:38 +0000 UTCGreat! You're welcome.
Mr Carlson's Lab
2019-01-16 19:16:58 +0000 UTCYou're welcome Jim!
Mr Carlson's Lab
2019-01-16 19:15:42 +0000 UTCWill build 2 of these, this circuit provides a lot of buffering! Really elegant design, thank you.
Inventor Pardue
2019-01-16 19:15:06 +0000 UTCI see an SDR Panadapter on one of the old boat anchors! Thanks for sharing the design.
Jim Edmondson
2019-01-16 19:08:20 +0000 UTCI'm sure you'll like it Michael. I have some Drake stuff in line for the bench, they should make some interesting future video's.
Mr Carlson's Lab
2019-01-16 18:45:13 +0000 UTCGreat Mark! Glad to be that drive. I should add... Pretty much the same process, take a few resistors (from a batch), and see how they stand up. Some metal film resistors (1/2 Watt) are amazing.
Mr Carlson's Lab
2019-01-16 18:42:09 +0000 UTCAnother great one. I feel like I'm at TEK in 1982, except with all the experience and material advances over the decades. Very same problems but much better solutions. I have one of those little rabbits running around in my head. Resistor breakdown potential. I am an experimentalist. I've been playing with my old Fluke 10K VDC PSU for a few weeks blowing up resistors. It would be fun to see you do a video about this topic. Especially in VT gear, I rairly find people that understand that a standard eBay resistor probably has a 200 VDC breakdown voltage. How do you select resistors that stay in one package at B+? You'd find a way to make something fun and that potentially will enabling people to get past that semester of lab sessions. Oh well, the once again man, your Pateron is dragging this old grumpy dog of the early digital days out of bed to live again. Many thanks.
Mark Bosse
2019-01-16 18:31:06 +0000 UTCYou're welcome Paul!
Mr Carlson's Lab
2019-01-16 18:30:31 +0000 UTCCan't wait to build this for my old Drake.
Michael Calhoun
2019-01-16 18:30:10 +0000 UTCThank you Paul, I'll build a few this weekend for my test equipment , and definitely a active probe, you can't have to many probes :) .
Paul Collins
2019-01-16 18:02:59 +0000 UTCYou're welcome Rob!
Mr Carlson's Lab
2019-01-16 15:48:53 +0000 UTCThanks Paul! Looks like a handy little device.
Robert Calk Jr.
2019-01-16 15:31:59 +0000 UTC
