Hey David so good to see you again! I hope you have been doing great and thanks for another video and that’s a great tip! It’s always nice when we get another one from you. I finished those Williamson amplifiers with the 1625s I went off the Stancor schematic and let me tell you they sound amazing, you were the reason I wanted to build Williamson and I do not regret it so thanks! I’d love to show you them maybe I could email you? Take care my friend
I would like to see your 1625 Williamson amplifier. As far as I am concerned, they are as good a power amplifier as any, regardless of the design and price. Mine runs 12-15 hours a day in my backhouse with KT66. TheAudioShop@SBCGlobal.Net
I didn't think about that. Thanks. Maybe the nylon washers are the best and leave out the o-ring? Since the only thing soldered is the center pin, I will likely take my main RF line apart tonight and just insert the nylon washer.
You got me going - I just went and measured the o-rings I have with a megger going to 5KV and I think mine are going to be OK. Still 20G ohm or better until I get it so close that it just arcs across in air. Still something to keep in mind. Thanks again...
Hi Andrew, Good to hear from you. You have done some marvelous work on GHz level antennas. I have watched many of your videos. I never advanced past 2.4 GHz as far as building my own antennas. I put up store-bought 5 GHz dishes on my house and share my Internet with two AirBnB properties I have near by and only have to have one fiber account. I did build a 1.4 GHz antenna for a radio telescope and use SDR and a PC to view the resonate hydrogen line in nebule. That was about a year ago. You mention the o-rings in your N connectors and another gentleman said he got Teflon washers in some of his PL-259 connectors so apparently some good manufacturers of these so called, UHF PL-259 connectors realized the problem with the shield shorting long ago. I did test these connections shown in this video with a megger and it would withstand 2.5 KV so It seems the o-rings I used are Ok and don't have too much carbon as mentioned in a comment below.... Anyway, take care and stay safe.
Hi Dave. I've been frigging with these frigging things for 60 years, since the days of the Belling-Lee 75 ohm PAL connectors for TV and FM. Did one the other day actually. I have always thought this style of thing where you fold over the braid and ram it home a terrible design, although I understand the design constraints, and now they seem to have made it worse! Best EJP
It is just that I followed prescribed directions and it always ended up shorted... what's wrong with this picture. A close visual inspection started making sense. For the large coax like LMR-400, for example, the dielectric presses right up against the center pin, covers it, and it works perfect. If one looks up connectors for RG-400, it is a completely different and new, screw on connector - oh well... so much for using the reducers - but it got me thinking how it used to work great and an inspection of the older connectors made it obvious. I normally use the large and stiff LMR-400 but sometimes that is like plumbing a house with 3/4 inch copper when you only need a small plastic tube like on a refrigerator. Anyway, good to hear from you. I have a few more idea for short videos. Since Microsoft took away the video editor that I used to concatenated videos, I prefer to just make one short one and post instead of going thru learning another video editor. Stay safe...
I am planning, when it cools off this afternoon... to replace the RG-58 in my truck for my mobile station, with the RG-400. RG-58 is good cable but honestly, I sometimes use it as a lossy connection between an exciter driving an amplifier but I don't need loss in my mobile setup. 🙂 Thanks for your comments. 73 WA4QGA
Hi Dave, Here's a video on the method I have been using with great success. However I did discover that those silver plated shells did not screw onto an SO-239 completely before getting tight. I had to order a special tap to clean the threads. Maybe the tried and true Amphenol connectors might have been a better choice. 73 WJ3U th-cam.com/video/O3u05ZTTTr4/w-d-xo.html
Hi Don, Indeed, the USA made Amphenol connectors are by far the best even if the dielectric is not PTFE. I have had new PL-259 and SO-239 connectors that simply will not tighten up the threads because of loose and-way-out-of-tolerance, conditions. Junk is what it is called. I just thought it might be helpful to someone going thru what I went thru, even with RG-58, to have the shield shorting to the center conductor because of the new PL-259 connectors and have some sort of solution. The new connectors (some) are actually quite good for LMR-400 size dielectric but, as the video shows, not so good for other uses. Amazing how a tiny design modification can change things in ways unseen at the time. No doubt, in my mind, designs, as seemingly simple as a PL-259 connector, were much better planned and thought-out many years ago. 73 WA4QGA PS - I did watch the BBI video. Can't say his method is bad but I don't see it necessary in most cases - maybe as he said, in rain and weather conditions on a vehicle, his method is probably better.
The problem is those are garbage connectors, they are Legacy style UHF connectors and you'll never see them used in a laboratory and for good reason, they're not constant impedance, they cause all sorts of impedance reflections, the more of these you have in the feed line the worse it gets and Lord help you if you get two connectors in Phase with each other. If you must use UHF connectors then you're much better off using the laboratory style clamp connector, these are improved versions of the Legacy pl259 and good to up to one gigahertz where the pl259 starts having real issues above 300 MHz of course this doesn't prevent ham from using them on 400 MHz which is ridiculous. Anyhow Google M&P clamp style UHF, you'll thank me later. It's all I use in my lab, in fact I use it on all my feed lines calling for UHF connectors. For the life of me I can't figure out why ham radio operators are still using this crappy connector probably have something to do with ham radio being overrun by conservatives who just can't stand new technology or any change to the status quo. The bottom line is the clamp style UHF connectors far better than even the crimp style connectors their impedance profile is superior to the Legacy solder type UHF connector add their just as waterproof as n connectors. Using these old style UHF connectors is kind of like buying a car that needs to be hand-cranked.
A video from my favorite amp Builder on TH-cam thanks for the video . I always learn something when I watch one of your videos😊
I always look forward to your posts!
It is so good to see you again..... hope you are doing well!
Thank you, sir. Always a pleasure to hear your thoughts and findings!
Hooray! An update!
Hey David so good to see you again! I hope you have been doing great and thanks for another video and that’s a great tip! It’s always nice when we get another one from you. I finished those Williamson amplifiers with the 1625s I went off the Stancor schematic and let me tell you they sound amazing, you were the reason I wanted to build Williamson and I do not regret it so thanks! I’d love to show you them maybe I could email you? Take care my friend
I would like to see your 1625 Williamson amplifier. As far as I am concerned, they are as good a power amplifier as any, regardless of the design and price. Mine runs 12-15 hours a day in my backhouse with KT66. TheAudioShop@SBCGlobal.Net
A quick heads up on o-rings.
Some have a high carbon content and will conduct under compression and higher voltage.
Lesson learned the hard way.
I didn't think about that. Thanks. Maybe the nylon washers are the best and leave out the o-ring? Since the only thing soldered
is the center pin, I will likely take my main RF line apart tonight and just insert the nylon washer.
You got me going - I just went and measured the o-rings I have with a megger going to 5KV and I think mine are going to be OK. Still 20G ohm or better until I get it so close that it just arcs across in air. Still something to keep in mind. Thanks again...
Maybe use Teflon o-rings?
rg400 I love it! I use it for all my jumpers...I get the pre-made ones from a guy on ebay that are very high quality.
I had something similar a few years ago with some screw on n types. The seller forgot to include the waterproof rubber o rings.
Hi Andrew,
Good to hear from you. You have done some marvelous work on GHz level antennas. I have watched many of your videos. I never advanced past 2.4 GHz as far as building my own antennas. I put up store-bought 5 GHz dishes on my house and share my Internet with two AirBnB properties I have near by and only have to have one fiber account. I did build a 1.4 GHz antenna for a radio telescope and use SDR and a PC to view the resonate hydrogen line in nebule. That was about a year ago. You mention the o-rings in your N connectors and another gentleman said he got Teflon washers in some of his PL-259 connectors so apparently some good manufacturers of these so called, UHF PL-259 connectors realized the problem with the shield shorting long ago. I did test these connections shown in this video with a megger and it would withstand 2.5 KV so It seems the o-rings I used are Ok and don't have too much carbon as mentioned in a comment below.... Anyway, take care and stay safe.
Super tip, thank you!
Some (but not all) of the Amphenol PL-259 connectors I’ve purchased included a teflon washer in the package.
Very nice. It appears someone saw the problem a long time ago. Makes us want to buy quality products even more. Thanks. 73
Great information. I am about to make new jumpers as well ! You just saved me a big headache ! Thanks buddy
Great - glad it helps - note the comment left about the o'rings.
Hi Dave. I've been frigging with these frigging things for 60 years, since the days of the Belling-Lee 75 ohm PAL connectors for TV and FM. Did one the other day actually. I have always thought this style of thing where you fold over the braid and ram it home a terrible design, although I understand the design constraints, and now they seem to have made it worse!
Best
EJP
It is just that I followed prescribed directions and it always ended up shorted... what's wrong with this picture. A close visual inspection started making sense. For the large coax like LMR-400, for example, the dielectric presses right up against the center pin, covers it, and it works perfect. If one looks up connectors for RG-400, it is a completely different and new, screw on connector - oh well... so much for using the reducers - but it got me thinking how it used to work great and an inspection of the older connectors made it obvious. I normally use the large and stiff LMR-400 but sometimes that is like plumbing a house with 3/4 inch copper when you only need a small plastic tube like on a refrigerator. Anyway, good to hear from you. I have a few more idea for short videos. Since Microsoft took away the video editor that I used to concatenated videos, I prefer to just make one short one and post instead of going thru learning another video editor. Stay safe...
I love RG-400. All my jumpers in the shack are RG-400. 73 Joe
I am planning, when it cools off this afternoon... to replace the RG-58 in my truck for my mobile station, with the RG-400. RG-58 is good cable but honestly, I sometimes use it as a lossy connection between an exciter driving an amplifier but I don't need loss in my mobile setup. 🙂 Thanks for your comments. 73 WA4QGA
Hi Dave,
Here's a video on the method I have been using with great success. However I did discover that those silver plated shells did not screw onto an SO-239 completely before getting tight. I had to order a special tap to clean the threads. Maybe the tried and true Amphenol connectors might have been a better choice. 73 WJ3U
th-cam.com/video/O3u05ZTTTr4/w-d-xo.html
Hi Don,
Indeed, the USA made Amphenol connectors are by far the best even if the dielectric is not PTFE. I have had new PL-259 and SO-239 connectors that simply will not tighten up the threads because of loose and-way-out-of-tolerance, conditions. Junk is what it is called. I just thought it might be helpful to someone going thru what I went thru, even with RG-58, to have the shield shorting to the center conductor because of the new PL-259 connectors and have some sort of solution. The new connectors (some) are actually quite good for LMR-400 size dielectric but, as the video shows, not so good for other uses. Amazing how a tiny design modification can change things in ways unseen at the time. No doubt, in my mind, designs, as seemingly simple as a PL-259 connector, were much better planned and thought-out many years ago. 73 WA4QGA PS - I did watch the BBI video. Can't say his method is bad but I don't see it necessary in most cases - maybe as he said, in rain and weather conditions on a vehicle, his method is probably better.
The problem is those are garbage connectors, they are Legacy style UHF connectors and you'll never see them used in a laboratory and for good reason, they're not constant impedance, they cause all sorts of impedance reflections, the more of these you have in the feed line the worse it gets and Lord help you if you get two connectors in Phase with each other.
If you must use UHF connectors then you're much better off using the laboratory style clamp connector, these are improved versions of the Legacy pl259 and good to up to one gigahertz where the pl259 starts having real issues above 300 MHz of course this doesn't prevent ham from using them on 400 MHz which is ridiculous.
Anyhow Google M&P clamp style UHF, you'll thank me later. It's all I use in my lab, in fact I use it on all my feed lines calling for UHF connectors.
For the life of me I can't figure out why ham radio operators are still using this crappy connector probably have something to do with ham radio being overrun by conservatives who just can't stand new technology or any change to the status quo.
The bottom line is the clamp style UHF connectors far better than even the crimp style connectors their impedance profile is superior to the Legacy solder type UHF connector add their just as waterproof as n connectors.
Using these old style UHF connectors is kind of like buying a car that needs to be hand-cranked.
Times Microwave.
U.S.A.
hard-line.