I completely agree with Tom. Carl! I'd leave it alone(for the reasons that I stated previously)! I expect that you would lose more than you would gain by adding an inductor!! "If it ain't broke don't
I don't expect that ANY of those are valid concerns at 1.3:1 VSWR!! Im not concerned by what is measured at the matching unit or a miniscule cable loss; just what is transformed back to the amp and i
That 1.3 is only at ONE frequency Charlie, he is not crystal controlled. What is the 2:1 bandwidth at the amp? Carl KM1H -- Original Message -- From: "Charlie Cunningham" <charlie-cunningham@nc.rr.co
Well, Carl the looses in 70' or even 200' of LMR-400 are so low at 1.8 MHz, even at 2.0:1 or 3.0 :1, if he can match it at the transmitter end of the line, it really doesn't matter! Charlie, K4OTV Th
Charlie youre continually missing the point; ignore cable loss period. The only issue is what impedance does the amp see from lets say 1800 to 1900 KHz? AND can the amp load into it without a problem
Well, I agree with all that, Carl. But Carl Braun, was reading "dead-flat" 1:1 at the transmitter end of his cable. I believe he is done!! The antenna Q is what it is! As for "improving his 2:1 VSWR
It may not be obvious but often you can get better bandwidth by NOT tuning for 1:1 at the desired frequency! Those familiar with the Smith chart probably already know this. A narrow band antenna will
I suppose I missed that part while doing things around here but this is the only pertinent info I can find from him. Nowhere does it say he has a 1:1 anywhere with the cap in the cabinet. Granted som
Wel, I agree with all of that, Roger. I plotted Carl's 45-j11 load on a 50 ohm Smith Chart, and it's right near the origin of the chart on a 1.3:1 VSWR circle. I'd need some more data points at some
The measurements are being taken, and have been taken, at the same point since the beginning of the antenna experiment. The ONLY difference is that the variable cap is now mounted inside the steel pa
Carl and Topbanders Here are the latest details and I will try and be as thorough as possible. Good news! I built my gamma cage and the antenna now performs MUCH better. Here's where I stand: 90' Tri
Inside the shack on the 1000D and the BIRD I see 1.1:1 Vswr at 1.800 MHz, FLAT 1.0:1 from 1.810 to 1.860 and 1.5:1 at 1.895 MHz. I'm eager to get back on the air tonight and tomorrow morning to see
I was pretty satisfied with this scenario so I mounted my variable cap on a 3/4" thick piece of Plexiglas to the backplane via Teflon bolts inside the steel enclosure. When I did this I saw my analyz
Exactly! All true and Tom is right on point! You have removed a lot of series reactance with that "gamma cage", Carl -as indicated by the required tuning C changing.from 160 pF ot over 400 pF. OF COU
That is the type of report I really like to hear Carl. All that work has paid off in spades. As you increase the number of radials the VSWR bandwidth might decrease along with the R which is normal a
I'm impressed, too! I believe Carl has it whipped!! Should be a really good transmit antenna for Topband!!b Changing to that multi-wire "gamma cage" really eliminated a lot of series reactance and lo
I'm sure it will play well in terms of keeping your transmitter happy but the relatively large bandwidth you are measuring is indicative of substantial loss in the system somewhere. This would be a
Good morning, JC Well, in its present configuration, Carl's antenna is not really a folded monopole, although it did start our as one when he had his gamma match connected at full height of 90'. At p