Hi Ed. Nice job but best place the SWR meter between your rig and your first box then retest the SWR (as the location where you are testing in the video is only testing the SWR of the dummy load). Cheers, Wayne.
Thank you for the information! Back about 15 years there was an article in either QST or CQ magazines ( can’t remember and can’t find the info ) on how to make these from Radio Shack parts. These appear to be a bit more reliable with the protector on the DC side and decoupling caps on the RF connectors. I have been using my bias T's to power an SGC 239 antenna coupler remotely that has been mounted in a CATV amplifier housing and utilizing a 106” CB whip to work the HF bands. Works like a champ with zero issues but I will be adding the MOV's , cap and resistor to my units as well as building a few more for other projects. Way back in the mid seventies I built a pair of crude bias T’s so I could use my SONY 920 U TV set on the back deck by sending its 12 volt power up the CATV coax. It too worked great as well.
Ed, As you are aware this kind of thing is commercially available but the cost for a ready built switch and Bias T is considerable. You prove with a little time and a few bucks in parts a great project that fills a big need can be easily created. I must say your presentation and workflow in the video is first class. Its like you have done this all your life. Thank you Sir for showing the true spirit of Ham Radio and doing so with much class and consistency. 73's ! Kevin WA5KW
Excellent! Thank you for your video. A very timely bias-T build, as I just had a cheap commercial one go bad (very noisy). I'll be building two of these ASAP.
That’s so cool 4nradio! I’m glad you found my video helpful. You’ll have to let me know how they turn out. Send some pics. My email is good on QRZ. -Ed W8EDW
@@edwhitney1862 Will do! I will be using mine for receive only, with Wellbrook magnetic loop antennas. I suppose I can reduce the voltage rating of the capacitors since there will be no transmit signals going through the circuit.
Nice build. Phil AD5X has so many good circuits. I built his switch operated multi-impedance transformer for short vertical antennas, works great. He’s an elmer even if he doesn’t know it. 😊. 73.
6.8 pF 1KV CAP are available thru DigiKey. Part #561R10TCCV68-ND. $1.30 in single quantity. $0.97 for 10. Through Amazon the same cap is $3.78 for one plus $7.95 postage! Thanks for sharing this project.
If you use RG8 size of coax. It’s only 1.37 ohms per 1000 ft (center conductor) and about .34 ohms per 1000 feet for the shield. So I am pretty sure you will have plenty of DC power at the antenna. Thanks for the nice comment! -Ed W8EDW
Great job Ed... appreciated... one question for you... does it matter which side of the capacitor, resistor, coil or varistor is connected. ie is there an in or out +/- side to these components?
Hi Ed. Nice job but best place the SWR meter between your rig and your first box then retest the SWR (as the location where you are testing in the video is only testing the SWR of the dummy load). Cheers, Wayne.
Thank you for the information! Back about 15 years there was an article in either QST or CQ magazines ( can’t remember and can’t find the info ) on how to make these from Radio Shack parts. These appear to be a bit more reliable with the protector on the DC side and decoupling caps on the RF connectors. I have been using my bias T's to power an SGC 239 antenna coupler remotely that has been mounted in a CATV amplifier housing and utilizing a 106” CB whip to work the HF bands. Works like a champ with zero issues but I will be adding the MOV's , cap and resistor to my units as well as building a few more for other projects.
Way back in the mid seventies I built a pair of crude bias T’s so I could use my SONY 920 U TV set on the back deck by sending its 12 volt power up the CATV coax. It too worked great as well.
Very helpful,now understand how to build the units .Thanks Phil G4DCI
Glad to help Phil. Hope to hear you on the air-! -Ed. W8EDW
Ed, As you are aware this kind of thing is commercially available but the cost for a ready built switch and Bias T is considerable. You prove with a little time and a few bucks in parts a great project that fills a big need can be easily created. I must say your presentation and workflow in the video is first class. Its like you have done this all your life. Thank you Sir for showing the true spirit of Ham Radio and doing so with much class and consistency. 73's ! Kevin WA5KW
Thanks Kevin! -Ed
Bravo ! Thanks for posting !
Thanks Alex! -Ed. W8EDW
Excellent! Thank you for your video. A very timely bias-T build, as I just had a cheap commercial one go bad (very noisy). I'll be building two of these ASAP.
That’s so cool 4nradio! I’m glad you found my video helpful. You’ll have to let me know how they turn out. Send some pics. My email is good on QRZ. -Ed W8EDW
@@edwhitney1862 Will do! I will be using mine for receive only, with Wellbrook magnetic loop antennas. I suppose I can reduce the voltage rating of the capacitors since there will be no transmit signals going through the circuit.
Nice build. Phil AD5X has so many good circuits. I built his switch operated multi-impedance transformer for short vertical antennas, works great. He’s an elmer even if he doesn’t know it. 😊. 73.
Thanks for the nice comment. I wish I had half of his knowledge! -Ed. W8EDW
Thanks! Very helpful video...need access to 12V at my antenna and this is exactly what I needed. de NY6C
FB job and a very useful addition to a shack.
Thanks David! -Ed W8EDW
👍Thanks for posting. Bias t is a useful accessory.
Hi Steve! Yep, I always wanted to build one. But thanks to guys comments, it made me do it. Hope to work you sometime! 73. Ed W8EDW
Love this learning tool for new hams like me. Thanks Martin KF0MOE
Thanks Martin. Ham Radio is tons of fun, isn’t it? Thanks for the nice comment and welcome to the hobby. We need more guys like you! -Ed W8EDW
Many thanks Ed, just what the doc ordered.. wb7pnc
Thanks Wil. It was a fun project! Thanks for the nice comment! -Ed W8EDW
How many watts can you use? Full legal?
Great how to video.
Easy to follow and well thought out.
Hi Doug. Should take full legal. Been using 600 watts for 5 months now. Thanks for the nice comment! -Ed W8EDW
6.8 pF 1KV CAP are available thru DigiKey. Part #561R10TCCV68-ND. $1.30 in single quantity. $0.97 for 10. Through Amazon the same cap is $3.78 for one plus $7.95 postage! Thanks for sharing this project.
Great video thank you.
Im curious the the maximum length of coax that could be used and still get useful power at the antenna? 73.
If you use RG8 size of coax. It’s only 1.37 ohms per 1000 ft (center conductor) and about .34 ohms per 1000 feet for the shield. So I am pretty sure you will have plenty of DC power at the antenna. Thanks for the nice comment! -Ed W8EDW
Great job Ed... appreciated... one question for you... does it matter which side of the capacitor, resistor, coil or varistor is connected. ie is there an in or out +/- side to these components?
Hi Arthur. No, all of the components are non-polarized. Let me know how your project turns out! -Ed W8EDW