Trombone capacitor for a small transmitting magnetic loop aerial
HTML-код
- Опубликовано: 28 янв 2021
- A brief video on the construction of a trombone capacitor for use on a small transmitting magnetic loop aerial. The capacitor should be suitable for more than 30 Watts, perhaps even up to 60 or 70 Watts.
Развлечения
Thank you for posting. I am just contemplating building my first trombone capacitor, and these are great ideas.
The Magnetic Loop is working well, I'll leave some comments about how it's performing, but first, I'm about to post a video comparing the mag loop to a doublet. Good luck.
very nice! and well explained
Very tidy. I've been doing something similar with copper pipe, but doubled up on the trombone idea to increase capacitance. Not tried it yet, its been one of the projects sitting in the shed for a while - you have inspired me to go dig it out and finish it off! Thanks for sharing.
Brillant idea and well constructed.
Charles, after a month, you certainly deserve more views/likes. It's a very well done vid as is your implementation of the trombone which is a credit to you. Must be the cleanest implementation I've seen!
Please be honored that I'll copy your design/method 100%.
Hat Tip to you, Sir.
I've had some copper pipe laying on the floor for months for the same use and your vid just showed a Cook Book method of getting on with my long delayed project. It should become a Classic!
I got sidetracked with an EFHW Inverted EL late last fall and then a nasty incidence with a Snow Blower rendered my 100Ft LMR400 rather usless for the time being. Ouch....
Again, good job and I just subbed.
Glad to read that the loop works well.
73
Russ in NH ..
I find it fairly fortunate that that conduit fit so nicely inside your outer trombone tubes. Have you published the specification for that tubing and conduit? This is definitely something I'm probably going to want to give a go.
I just looked for a part 2. I'm quite curious as to how your Loop turned out. I can just kick myself because I had a Vacuum Variable Capacitor years ago and gave it away. I want to build a Loop someday so I've been watching for Capacitor ideas.
Are the two capacitors in series (both fixed legs of the trombone connected each to one end on the big loop)?
👍
have you measured the capacitance of the cap?
very nice de VU3FTP
Two sets of this in parallel, may tune 80 meters
what bands will it tune with that capacitor?
It was meant to tune through the 40m band and that is exactly what was achieved.
@@mw0gbr1 nicely done!! How did you size the capacitor for the band?
I designed for 40m band and it worked a treat!
I used to basic maths found on the internet for calculating the capacitance, it's just the plate size according to the size of pipes used. It worked well.
@@mw0gbr1 How long were the "trombones"? And more important, what is the highest freq you manage to have the magloop resonating? In other words, what is the minimum capacitance you obtained?
No measurements?!