Glad you liked the tester! Stay tuned to the channel as I will be adding an RF amplifier to increase the sensitivity for use with low power transmitters.
Thank you Hman! Something to keep in mind. Keep the coax leads short as possible. Additionaly, I am using 100 watts of transmitter power for this demonstration. You will need enough power to get a full scale meter deflection when calibrating the tester. QRP power will not work. With low power, a active amplifier should be incorporated in the test device. I may do this in a future video. Let us know how it works out for you!
@@handyman7147 Actually, I just purchased the Surecom S11 FS Meter and will do a video on it. It has an rf amplifier built in. www.amazon.com/Mcbazel-Surecom-Portable-Strength-Antenna/dp/B092SCDDWH/ref=cm_cr_arp_d_product_top?ie=UTF8
Wow, I really appreciate your approach here. I have built some things in the past. Really well done. Thank you for sharing...hope to build one for delta application. I am also interested in the construction of your sampling cored! Thanks Again. 73
Thank you for your kind words. I hope to do some more vid's on DIY projects. Also, I may do a followup vid on how to construct those split toroidal transformers with the SMA connectors.
Glad you liked it Bob! Stay tuned to the channel as I am coming out with a improved version which will have an RF amplifier to increase the sensitivity for low power transmitters. The frequency I used was 14.25 MHz I only intended it for use between 1 to 30 Mhz.
Hi Joe. Got them from DigiKey. www.digikey.com/en/products/detail/fair-rite-products-corp/0444164181/8594097?_gl=1*lkn6ue*_up*MQ..&gclid=EAIaIQobChMI2feL75D_iAMVMjYIBR0fsAFTEAAYAiAAEgJvxPD_BwE
I created the schematic from various designs published long ago. For this passive device, a 50 ohm resistor is not recommended due to heavily loading down the sensitivity of the meter. In some designs, you may also note a diode placed across the meter to protect it from excessive current damage. But, this too decreases the sensitivity of the meter and is unnecessary if you exercise care and set the pot all the way down before energizing the coax under test. The 10 turn winding, on this toroid, presents very poor impedance match across the HF spectrum and therefore, the toroid if needed should be terminated with a 50 ohm resistor. See my video where I implemented this. ua-cam.com/video/DrjW_t_1qq0/v-deo.html
@@rfburns3472 Thanks rfburns 3472 I don't mean the capacitor in front of the diode, I mean the ON/OFF SWITCH between the rotary potentiometer and the ampere display on the diagram! It also says 150 but without a designation...? Sorry for my bad English, but great video and great idea with these two measuring probes! 73 Daniel
@@ugiukito9449 OK Daniel I understand now. It's a 150 ohm resistor and switch that will change the sensitivity of the potentiometer adjustment. It's optional and only needed if you have very high currents coming from the toroid sensors.
Thanks! this is great practical way of testing them!
Glad you liked the tester! Stay tuned to the channel as I will be adding an RF amplifier to increase the sensitivity for use with low power transmitters.
An excellent KISS gadget. I will make one. Thanks for sharing 🎉
Thank you Hman! Something to keep in mind. Keep the coax leads short as possible. Additionaly, I am using 100 watts of transmitter power for this demonstration. You will need enough power to get a full scale meter deflection when calibrating the tester. QRP power will not work. With low power, a active amplifier should be incorporated in the test device. I may do this in a future video.
Let us know how it works out for you!
Thanks a lot for the tips. Looking forward to seeing the active amp.
@@handyman7147 Actually, I just purchased the Surecom S11 FS Meter and will do a video on it. It has an rf amplifier built in. www.amazon.com/Mcbazel-Surecom-Portable-Strength-Antenna/dp/B092SCDDWH/ref=cm_cr_arp_d_product_top?ie=UTF8
Wow, I really appreciate your approach here. I have built some things in the past. Really well done. Thank you for sharing...hope to build one for delta application. I am also interested in the construction of your sampling cored! Thanks Again. 73
Thanks Mike for your positive comments! I still hope do a video on how I constructed the toroidal sensors.
Pretty cool and neat! Would like to see more of the diy things especially sma toroidal clips. Thx :)
Thank you for your kind words. I hope to do some more vid's on DIY projects. Also, I may do a followup vid on how to construct those split toroidal transformers with the SMA connectors.
Humm,you give me an idea,Im gonna try this with my picoscope and ignition coil pick up sensor.
Good to hear that! Hope it works out for you.
I like this circuit! Thanks for posting it. What was your test frequency, and is that important? 73
Glad you liked it Bob! Stay tuned to the channel as I am coming out with a improved version which will have an RF amplifier to increase the sensitivity for low power transmitters. The frequency I used was 14.25 MHz I only intended it for use between 1 to 30 Mhz.
A video showing how you built the clamp on sensors ??
I really would like to do the video. Just need to figure out how to do the camera shots hopefully soon.
What type of clamp on ferrite core did you use for the sensors? Informative video THANKS
Hi Joe. Got them from DigiKey. www.digikey.com/en/products/detail/fair-rite-products-corp/0444164181/8594097?_gl=1*lkn6ue*_up*MQ..&gclid=EAIaIQobChMI2feL75D_iAMVMjYIBR0fsAFTEAAYAiAAEgJvxPD_BwE
@@rfburns3472 Thanks for your novel approach with this project and expedient response. Joe
@@joes6718 Your welcome Joe. I am working on a tester with a amplifier for folks who have very low common mode currents.
Anyone try using a multimeter to skip construction of the meter circuit and box?
Where did you get the schematic? In other schematics I see a 50 Ohm resistor in parallel just behind the pickup coil
I created the schematic from various designs published long ago.
For this passive device, a 50 ohm resistor is not recommended due to heavily loading down the sensitivity of the meter. In some designs, you may also note a diode placed across the meter to protect it from excessive current damage. But, this too decreases the sensitivity of the meter and is unnecessary if you exercise care and set the pot all the way down before energizing the coax under test.
The 10 turn winding, on this toroid, presents very poor impedance match across the HF spectrum and therefore, the toroid if needed should be terminated with a 50 ohm resistor. See my video where I implemented this. ua-cam.com/video/DrjW_t_1qq0/v-deo.html
Hello RF Burns, question: I don't understand this "150" on the DPDT switch? Is there a 150 ohm resistor built in?
Hello and welcome! The pole at the top of the DPDT switch has a 150 pf capacitor used to couple the RF energy to the diodes for rectification.
@@rfburns3472 Thanks rfburns 3472 I don't mean the capacitor in front of the diode, I mean the ON/OFF SWITCH between the rotary potentiometer and the ampere display on the diagram!
It also says 150 but without a designation...?
Sorry for my bad English, but great video and great idea with these two measuring probes!
73 Daniel
@@ugiukito9449 OK Daniel I understand now. It's a 150 ohm resistor and switch that will change the sensitivity of the potentiometer adjustment. It's optional and only needed if you have very high currents coming from the toroid sensors.