A moron that makes crappy uploads to get a few cents from RU-vid I’m 75 now and got my ham radio certificate when I was 16 I built a few rigs in my life and have a lot of friends that also are builders, This is absolutely stupid waste of time.
For crap sake, you are inventing the wheel all over again, high voltage variable capacitors are on eBay some of them are vacuum capacitors for 20kV 25pF to 1500pF, what is wrong with you?
I'm not inventing anything. I'm using what I had on hand to make an alternative. You clearly didn't listen to what I had to say in the video. Pay attention. So glad I'm not making these videos anymore so I don't have to listen to armchair quarterbacks put their two cents in every day. Don't like what you see? Go watch someone else.
I'm late discovering this video but I am about to recap my 2220B this weekend. I've already cleaned out the pots (this greatly improved the sound and removed most of the scratching) and re-lamped all but the dial and stereo indicator light (LED is too bright). My only question is: how do you determine that transistors need to be replaced and which ones? Thanks. Great job with the video.
Nice video and good craftsmanship on the antenna build, Derek. If you enjoyed the lower recieve noise, just wait until you throw a 20 meter mono band yagi on top of a 40 foot tower! I was blown away at how quiet it was compared to my ground mounted hustler 5BTV. Speaking of the 5BTV, I recently relocated it to 16 foot above ground and following manufacturers installation recommendations, ran several tuned "raised" radials for each band of interest. It worked fine, and was quieter than when on the ground, but not much. I then moved it to 12 foot above ground and attached the 10 foot rigid steel mast to my RV's bumper and a unistrut bracket at the roofline, mast not touching the earth. I then bonded my radial plate to the metal skin of the RV and completely removed the raised wire radials. This is working extremely well and dare I say BETTER than any combination previously used. SWR is < 1.5 on all bands except for 40 meters, which is at 1.7. The takeoff angle must be better for DX than before, due to the locations of contacts I have made now compared to being ground mounted. I haven't tried to model it due to not having the program yet, but I will try to download the modeling software you gave the link to in the description, although, Im not sure if it's possible to model a 30' RV as a radial field. 😅 Anyway, thanks again for taking the time to document and explain things! Experimenting is truly the best part of the hobby, or at least it is for me. 73 DE KN6UIZ
Love the video. I have been doing experumenting with j poles fopper and ed fond pvc style. Just built a quarter wave and i love it. I ned to revise how i did mine a little but love the video. Straight to the point and simpke.
Thanks for technical explanation. Much appreciated. However, no doubt you realise by now (3 years ago ?) that you slipped a decimal place in your calculations. At 8:00, up pops the line with 1/4 wave length calculation. 0.172 metres should be 17.2 cm …. they don’t cal it “centi” for nothing 🙂 ….. or you could have left it as mm. Assume you’re USA, so maybe you’re use to using Imperial units, and are metrically “challenged”. 😆 I’m from Australia. I read down thru the first 20 comments or so, on my iPhone and couldn’t see any pick-up on this point so posting. I notice one commentator was Canadian (metric), but no mention ?
Ok … I should have kept watching … corrected. Perhaps you should have subtitled the correction immediately instead of waiting 45 secs in the video, and then only leaving it up for 10 secs.
I hate rosin core solder... it fucks me off cuz im not that good at soldering to begin with. However I've found that one drop of 85% phosphoric acid diluted 5 to 1 works wonders. Dip the tip in the acid before tinning and a couple drops in my flux is the shit
There are online antenna calculators to work out the measurement of antennas ,just go tell us the measurements, never mind the science lesson get on with ,,I skipped to half the video
I dont think that wires has to be there as long as you touch the tube with center of pl 239,s or whatever your useing and have it soldered that’s all that matters
Absolutely BEAUTIFUL! Such a fantastic display of the marrige of math, geometry, pyshics and electronics. And it all begins to feel more intuitive. It brings my world of acoustic transmission to life.
if i want to make a higher capacity capacitor, aka more pico farrads, whats the approach ? just add more plates and larger surface area ? very nice construction you have !! well done ! im experimenting with resonance ! and looking to atain a use'able variable capacitor with say 0-1000 pf or more. but i think 1000 pf is a good start.
Greetings from Colombia. I am new in ham radio, I want to make and install my own antenna for 20 meters band, and I don't see all the real dimensions of your antenna and others details. Why two holes? What is the diameter of your antenna? What material is using for that? Exactly how meters tall? Why 3 radials instead of 1 radial? If you offer this details in a blog, please tell me the link. 73!
First one of your videos that I have caught and your monopole sounds like an interesting build and the performance comparison to your attic antenna was informative.
Thanks. I've been making electronics videos for element14.. that plus the "real" job, doesn't leave much time. I hope to have more time this year so will probably get back to it.
It is a violation of FCC regulation for a homeowners association to require or attempt to stop a resident building and operating ham radio, and all of its required instruments, including antennas. It is considered an emergency communication method, and any local authorities that attempt to prevent a licensed ham operator from operating are in open violation of federal law. Regardless of any HOA agreements.
Thank you so much. I will copy this in full. Could you please post a brief video of your completed and installed capacitor? I am sure many of us would like to see it in action and so learn even more.
Considering how much space you have in your attic you could install a dual band slim-jim or a 7/8 vertical or a j-pole. at 70cms you can get some serious gain from a vertical G7VFY
For your four ground plane radials is the measurement from the edge of the aluminium base? Or do you measure from the edge of the So239 socket? They are significantly different numbers. Thanks Derek ZL1DCB
