Remote Controlled Ham Radio Coax Antenna Switch Will Handle 1.5KW
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- Опубліковано 3 гру 2020
- Jim Heath W6LG shows the remotely controlled coax switch for ham radio antennas. The switch box has 5 vacuum relays that can handle 1.5kw with a large margin.
- Наука та технологія
Welcome back Jim how are you feeling how's your health doing good I'm so happy you came back you make me wait about you let me know how you doing
Hi, I am thinking about a "private" video to answer that question. I may set that up with a special email address. Thanks again for your kindness and concern! 73, Jim
It'd be good we could communicate better again at your email it'd be good for communication that way hope you feel better
And Merry Christmas Jim
Hey Mr. Jim. Looking good, there. I am always floored when you show your shack. Be well, merry Christmas. KC3BXZ Joe
I am filming now about what's under the desk. Should be good for a few laughs in the beginning. I did some special grounding that may help some others. Thanks! Sorry about the delay in answering. Lots to do and not much time. Thanks, Jim
Jim I add my appreciation for all you do. I am thinking of your health situation and trust that your medical "team" has everything figured out. 73, Al W1VTP Manchester, NH
Good to see you Jim. You look great! Always happy to see you feeling better. Thanks for the vacuum relay tutorial.
Wow! That is some relay box and you are thinking outside of the box. Brilliant Jim.
Good to see you again, Jim. Thank you for the interesting and also timely video. Stay safe!
Thank you. The next video will come from "under the desk". 73, Jim
Hey Jim, glad to see a new video. I hope all is well around your way. I wanted to comment and tell you I appreciate all you do. I have followed your channel for quite some time. I have operated on the 11 meter band for 23 years (started at 13yo) and decided to make the leap over to amateur radio. I passed my technician and general class exam yesterday, so just waiting for my license to hit the database. Thanks again, 73
Was starting to wonder about you the last couple of months. I'm happy to see another great video!
Hello Jim, great to see you doing videos again. I read about your health situation and glad to see you are back at it and looking good! Happy Holidays to you and yours. Thanks for all you do 73, David W5DPV.
Hi Jim, glad to see what you've been up to! Merry Christmas to you and yours. 73!
Great to see you again Jim, glad you are well. Nice build, I want to do that type of set up on my beam so I can use one run of 7/8 heliax I was given to switch from vertical and horizontal and to my fan dipoles.
Glad to see you back on UA-cam. I loved this project, can't wait to see it mounted and running.
I just received my ARRL upgrade to Amateur Extra class Q&A book today. I'm still waiting on the Manual, funny thing, order both at the same time. Keep making videos and 73 KB3YJU
Looks a substantial bit of kit. Well done Jim 👍🏻
Hello Jim, very nice job. Back in the '70s/'80s I received a rf test set for which I had to perform an acceptance test.
A little while after taking possession of the rf test set, I believe I had problems with one of the compact flat packaged relays. When sourcing a replacement I found a relay with the same specifications and size, but it was a 'yellow' sealed nitrogen filled relay. I changed all 6 signal relays with the nitrogen filled relays and never had any contact problems again with the equipment. A few years ago, I looked for those nitrogen filled flat transparent yellow tinged sealed cased relays for a project I had in mind, without success.
Back in the '70s/'80s there were many new high tech components manufactured, sadly quite a few of these excellent components have sadly disappeared.
WOW Jim, very nicely done. beautiful construction job.
Hi Jim, good to have you back. I am back down in Indio, Ca for the winter with my small station. 7300 with a HiQ screwdriver vertical antenna. Cheers and good health! VE7BFM/W6
Just subscribed 👍🏻 Looking forward to watching more and reviewing past videos.
Good video. I learned something. They say you should learn something new each day. I was contemplating building a manual coax criss cross switch and hadn't figure the current difference from 60hz to 28Mhz. Your video prevented a failure.
Merry Christmas. 73 W9DLP
Thank you, Jim. As a new ham myself, I am grateful for your generosity in sharing your experiences, wisdom and knowledge. Best wishes to you.
Bob Triggs
W2YBK
Thanks Bob. So many guys helped me in Burbank. I am trying to pay it forward a little. Let me know what you would like to see. In any case, have fun Bob! 73, Jim
Thanks for that, Jim. I loved the video and your manufactured auto switch. Have a Merry Christmas and hopefully a happier and more free New Year
73’s. Bob Runge W1LSZ
Always good to see you in another video, Jim! Merry Christmas to you and your family from your friend in WV, W1WRE, 73.
Hey Bill. Merry Christmas and Happy NY to you and the family. Stay safe...and away for a few more months. We should be in line for a vaccine soon. I am working on the next video from under the ham desk. 73, Jim
Hello Jim, nice to see from you again. Happy weekend from Uncle Günter.
Hi Jim, so very pleased to see you. I cannot thank you enough for the expertise you have shared with us all. I hope you are well Jim my love and appreciation as always, take care of yourself. I think you are very wise to stay home as much as possible during these uncertain times. I would love to think that next year we could make a contract on HF. To better times Jim 73
Happy to see you again sir.73 from Romania.
Very interesting video Jim. Stay well mate.
Thank you for making these videos. You inspire me and educate me. Greg, NB8X, Saint Joseph, MI.73
Always enjoy your vids. A great Elmer.
Thanks Jim great video, it's great to see you have a great holiday stay safe and healthy God bless!.
Thanks Jim! I am very thankfull you for these DIY
Thanks to you for watching. More to come with reasonable explanations. 73, JIm
Hi Jim, Interesting video and perfect timing for me as I'm looking to build a remote antenna switching system in the new year! I heard Slavko S57DX work you on twenty a few weeks ago so I take it your new mast and beam are working well! Good health & Good DX Jim. 73 Tom.
Great to see you Again Jim had me a little worried
Nice project! Have fun using it!
Hi,good to see you back, interesting video, bit beyond my building skills but good to know, thanks from Rotterdam.
Also the nc contact is usually rated at half the current. Its only held with a spring. The no contact when energized is held with a magnet.
Nice relay box Jim. I hope you are doing well. Glad you are staying home and staying busy. We are doing the same. Stay Safe. 73 Joe
What a neat project! Those vacuum tube relays are really something! 73!
Yes they are! You can find them on Ebay from Russia and other places. 73, Jim
Jim's back!!!!
You look good Jim !!!
Nice little switch, ...liked the relays - I've never seen them in vacuum tube configurations.
You can find them on Ebay. They work great and can stand some really high power. There are 2 versions; large and small. 73, Jim W6LG
@@ham-radio Thankyou Jim
Keep thinking up good things for us. I enjoy the videos.
Thank you for the video they are always great.
Wow, fantastic work! Thanks for explaining everything!
You are very welcome Alex. Watch for the next couple of videos about station grounding. I hope to have some fun with that subject. 73, Jim
Great camera work
Jim, thank you very much. I learned a lot with you, and I'm still learning!
Well done.
73, take care. 9A3GVD, Dom
We are all learning. We learn by doing. Thanks Dom & 73 from your friend Jim
Love watching your videos thank you for doing this for us. 🇺🇸
Fascinating! Beautiful design/work. Thank you for sharing. 73s
Many thanks! 73, Jim
Hi, Jim. Nice video.
Hy Jim so glad to see you again hope you and Family are doing well. Like always new things to lear with my Elmer God bless 73 de KB2SVC
Thanks for this excellent video! Perhaps at some point you could share with us how to build one of these switchers, and where we might be able to source the parts? All the best!
jim in-joy your video lot keep show us more Rob Queensland Australia 73 JIM
This video really points up the overlap between the ham community and the maker community, which I didn't realize until I became a ham later in life. I love it!
Those relays are monsters! And, in the spirit of the video, I'm wondering if I could make some vacuum tube relays of my own. Hmmmmm...
Sure you could. The smaller version are really handy. I am going to buy a few more for other projects. You too might want to get the smaller relay for an antenna switch. In any case, have fun building something. Thanks for watching and writing. 73, Jim
@@ham-radio As it turns out, there is plenty of detailed information out there on ways to go about making your own vacuum tubes of all sorts--from light bulbs to tetrodes and all sorts of other interesting stuff. It had never occurred to me to look!
And now my list of future projects has grown by several.
Ah, so many projects, so little time...
73
My experience says that most problems with antenna switches are either moisture or hot switching (could be because of RF in something causing it to switch such as a band decoder or power supply). I have used regular hermetically sealed Omron 16A or 2x8A relay contacts in all my switches and have never ever had any issues and I have A LOT of relays at SJ2W. When I started selling some of my switches I even went to a guy who has a big amp and ran them for quite some time with 6kW on 20m and no issues. However if you get VSWR and don't use vacuum relays you will have problems. My whole station is fully automated so no mistakes can be made transmitting on the wrong band, without an antenna etc.
I even use a regular 16A relay in one of my amps as TX/RX relay and it still works 8 years later I installed it, but I have proper sequencing. So again, I think 95% of problems are either hot switching or moisture.
WX0B switches I have not very good experience with, I would guess it might be a lot because of the open relays.
Would like to see a bill of materials and a how to build video. Appreciate your time and knowledge, 73 N4JOM
Thanks for the video 👍
Can you post a schematic of the control logic for your relays? Or better yet another video! Good to see you holding up CA.
Glad to see you are ok Jim. Lost 2 friends in November. Looks like a light at the end of the tunnel. Love the switch. So will the light shine if there’s electrical load over individual antennas. Such as static electricity ?
Personally I like the box. I'm a beginner I'm just now getting back into radio. I enjoyed 11 m as a teenager but work quickly took that over and made it disappear. Not to mention the fact I've moved about every 3 to 5 years my whole life. So the idea of a base station wasn't really practical. I'm wanting to get back into all forms of radio. I still enjoy the CB which I purchased after gmrs. Very close to being able to get my technician. And I don't want to stop there. No I was weighing the cost of running separate cables. My first run of cable is the lmr400. In order to get out of the valley then I'm in in the Appalachian mountains. My run from my home to the base of my tower is going to be 300 ft. With a 60 ft Tower I'm gaining nearly 300 ft in straight up elevation. So I believe it's acceptable. But an option like this would definitely cut down the cost on running multiple cables for that sort of distance. The question is what little box like that cost?
As always, a great learning experience! Great to see a new video. As a new ham, you make it easy to understand and follow along! Thanks!
Thanks for the video. My only comment is that relay contacts are rated at how much current they can switch (make/break) over a certain lifespan (like 100k operations). Breaking high currents is especially bad for creating high temperature arcs of several thousand degrees, which eventually destroy the silver contact points. As long as the antennas are not switched hot (while transmitting), the general purpose relays should be fine. I have been using GP relays for years at full legal power with no problems. I use DPDT relays for each antenna line, with each relay pair wired in parallel, which halves the current at each contact point. Regards, N4DXC
Thanks Bill. I don't believe that I ever hot switched the relay contacts. But, anything is possible. I commented to another ham that a person could write a PHD Thesis on relays. I used a vacuum relay in one amplifier and may put one into an amp that I am building from the remnants of one that did not survive the move in good shape. I did not get the new relay box installed yesterday. I hope to do that today. I had another tooth fracture due to the osteoporosis and that slowed me some; it really hurts. I hope to show the underside of my ham desk and the grounding system in the next video. I don't believe in station RF grounds. But, I did it just to see what happens. Thanks again Bill. 73, Jim
Now it's time for some long term testing ;-)
Hello, just stumbled on your video as I am looking to get into HAM radio. Really nice build. Some thoughts, the vacuum relays to my knowledge have a vacuum to handle high voltage switching in a relatively small space. The size of the conductors are what mostly determine the current. When I used them on a design for work they were really expensive with a long lead time. A potential alternative would be mercury wetted reed relays for a lot less money. Also, I’d suggest using DPST, or DPDT relays. Then have one contact for the main circuit, and the other to provide remote indication/confirmation. Thank you for sharing.
Those relays cost almost nothing and were from a good friend in the Crimea. I have built 3 of those boxes using 15 relays and all work great. I have an old, but new to me, amp with a large open frame relay that is slow and noisy. I will change it with 2 vac relays that close quickly without noise. Thanks & 73, Jim
@@ham-radio could you provide the part number and where you got them? Sounds like I could use them. Thank you.
Welcome back Jim - Question regarding Return Loss
I thought one wants an RL value as high as possible like 40dB best I can get. That is because RL is measuring how much energy is coming back vs going out. We don't want much if any RF coming back (miss match) so the larger the dB value means not much coming back. RL is indicating the difference in outbound vs reflection.
Do I have it wrong?
Bob - W6OPO
A project of this kind is right up my alley, Jim. I'm currently working on a mag loop for 20m. Should you have the opportunity and wish to do so, it would be great if you could call out some part numbers for the relays. On the other hand, having given a clear explanation of how to de-rate AC relays for HF work, anyone should be able to do the same when doing their research.
73,
John, KJ7RDV
This was really interesting. Where do you buy those silver connectors and coax that you use?
Hi Jim. Interesting design. For the measurements, did you have the other port open circuit? I assume so based on your use of 1/2 the return loss to approximate the insert loss. Can you show the return loss with the other port connected to a 50 ohm load so we can see how well the switch is impedance matched.
HF antenne projects! I am a starting HAM radio amateur. Thanks for Sharing your knowledge ! Kind regards, Theo PA0HTY
Thanks for the video Jim! I enjoyed seeing your project. I would be interested in learning more about the relays you used and where you can find components like that.
Jim do you happen to have a schematic available? Maybe a few pictures of the switch innards? Not asking for detailed build instructions, mechanically I think I can handle it but I’d like to see a more clear shot what’s going on here. Also any advice on how to pick other relays that may be well suited for high power ham use? I believe these relays you have are either hard to find or priced at unobtainable levels I’m not sure their part number or exact spec, thank you for all your efforts sharing you knowledge with the world! 73 de Seth - W8FG
jim question, where did you get the relay tubes at . and what are the numbers on the relay tube. . i really enjoyed the antenna relay box project .
bob/kb5sqg/Granbury tx
Good to see ya Jim, looking good and stayin busy....
"73" ....N8QZH
Thanks again for your wishes and help. 73, Jim
Jim, nice job on the HF switch . Can you provide a diagram on your VNA test setup? I'm curious as to why you made an S11 Return loss measurement instead of an S21 insertion loss measurement.
Maybe he was testing the coax going to his tower or he couldn't access the other end. Measuring return loss÷2 is should give exactly the same result as insertion loss. You just short the far end and measure the return loss from this end and divide by 2 to give insertion loss.
Is there another video where you explain how the relays are remotely controlled?
Nice switch! 73 de VK2AOE
What would it cost to build this today if one did not already have parts on the shelf in the garage?
do you have any idea on how to switch between an tx amplifier and a rx pre-amp on the same antenna triggered by the ptt?
Jim, I have a couple 12vdc relays with contact ratings of 12vdc 250a. do you think they’d work? I believe they are intended to connect / disconnect the battery in a car or truck so they are pretty heavy duty.
Sure. I squared R. 73, Jim
Awesomeness!♡♡♡
🤜🏻👍🤛🏻
Brilliant construction G4PEY
Skin Effect plays a major role at impedance. Somehow people forget about that.
I was using a switch for 20 Years , equipped with small AC 220V 16Amp 2$ relays. NO FAULT EVER . Well the limit here is 750W , but i am sure they would even have been okay at 1500W . The Problem of these relays you showed is the OPEN FRAME .. the is prone to dust and moist which will build up resistance and ..therefore after time heat and oxidation. Vacuum relays are made to switch high speed under load. I replaced the switch some years ago due to rotten SO239 Sockets. Now i guess the newer switch with 32Amp surplus 4$ relays will live way past behind my lifetime....
Sounds good. Relays...I think I said that a person could do a PHD thesis on relays. A lot goes on in one of those things...also the open frame issue. Thanks Harald 73 Jim
Another good video. I am considering making my own antenna switch since the prices are $250+. I started looking for this was when I was trying to mount radios and antennas in my truck. Primarily it would be nice to run one feed line out of the truck and switch the antenna feeds outside of the cab (routing cable of any kind out of a truck can be “fun”). Where did you find the current capacity at HF? Thanks again, and all the best! 73 de KI5HXM
If I had to build one today with limited money, I would use the Russian vacuum relays that are the small version of the ones that I did use. The small relay from Russia and Ukraine easily handle legal limit. The ones that I used can handle about 6dB more. 73, Jim
@@ham-radio thanks for the reply. I am intrigued with the suggestion of using vacuum relays. Where can I go to get smart on those devices (not asking for you to spoon fee me, i am a retired electrical engineer and have a lot of the basics that i need. Of course making a switch of this sort could be over kill for a mobile rig in a truck. Perhaps a simple Alpha Delta switch with multiple coax leaving the cab might be more reliable (less failure points). Even if I don’t go this route, I am in Ham Radio to learn!
Nice...............
Hey Jim,
Odd question, but could this be run in reverse so to speak. I'm looking for somthing to switch between radios on the bench. I'm only running 1 antenna, but several radios.
Thanks, I appreciate your time
No you can't use them to switch radios because they are only one contact if you switch radios you want to have just one radio connected to the antenna rest of them must be grounded.
In edition to that each relay must be separately shielded or you will get way to much RF leakage from one radio to the other .On 100 wats of power you don't need vacuum relays regular
single pole double throw will do just fine .Jim use vacuum relays because he is switching KW or more at antennas.
@@georgezardecki5888 thanks for the reply. I had a feeling that would be the case. Would be awesome if it would work though.
@@luke8210 Luke send me email I can make diagram how to connect several radios to one antenna 73 George N9VTB
@@georgezardecki5888
What's your email address?
How far apart on the tower are your antenna's
After 38 years, I had to move. The antennas were not stacked but were on separate towers. The 20 meter antennas were 20 meters apart in the same horizontal plane using matching networks, delay lines, rotators to get about 10 to 11 dB gain as fed from hardline in the ground. 73, Jim
CQ REVEIVED...WP4MIX, QSL. 73
nice work but looks like the Impedance is off.
Great video! I recognize those "green and mean" relays .. they are Russian made. These relays are great for antenna switching but should not be used as a TX/RX relay they have a release flight time is a week and a half. KC8ZUL columbus ohio.
You are right! Good for band switch, antennas switch but not hot switching or TR switch. Thanks Gerry...good information and help! 73, Jim
ITS THE fLU!
You will be fine then as long as you have had your Flu Jab. Maybe you could go and help out down at the local Hospital Covid ward, I am sure they could do with your help seeing as you would be immune to it. Go on then what you waiting for go save some lives.