You can indeed do it this way, but the swr increase may be enough to create problems. This drove us nuts one time at a multiop down in Mexico. We were feeding a TH-6 and a 40-2CD with two 75 ohm hard
Assuming matched antennas and raliziong that also reflected power will be attenuated, expecially at 440 MHz. Extra losses because of an 1:1.5 SWR produced by a 75 OHm cable use are neglegible and muc
Mike, You don't state which manufacturer's hardware you have or what yagi design they are (or if they're yagis for that matter). Assuming they have some sort of adjustable matching network on each, s
Roger, I think that you're right. I must have read the table wrong, showing that I would have 6db of loss. After reading your mail, and rethinking this, adding the hard-line and the mismatch losses o
I agree with the conclusions but it is important to remember a few things. The actual mismatch normalized to a 50 ohm system ranges from 1:1 to 2:1 at the transmitter. The transmission line sees a 1.
Hey guys, he is operating six meters, two meters, and 70 CM. Not 80 through 10. He isn't going to be able to use HF solutions, and it is unlikely his rig has a pi-network with tube finals. 73, Tom W8
Is there a solution for matching 75 ohm hard-line to a triband antenna? I have a 6 meter, 2 meter and 440 antenna on my tower with 100 ft of 9913 feeding it. At 440, it's probably about 6 dB loss. I
Sure. Just plug the feedpoint pigtail/rotator loop (50 ohms) in the end of the 75 ohm hardline and live with a little increased SWR. Cheers, Steve K7LXC Tower Tech
There are two mismatches: one at the antenna and one at the transmitter. So the mismatch is a bit more. I'd pop for the $30 - 50 in LDF-4 @ hamfest prices and eliminate these mismatches. Bill, N3RR e
You could just feed it with the 75 ohm cable, the SWR on the 75 ohm cable will only be 1.5:1. Keep in mind the 50-ohm normalized SWR would be as high as 2:1 on some frequencies with 50 ohms at the f
Tom, Correct me if I'm wrong but I think tube finals will load into 75ohms as easily as 50 ohms and antennas with a hair pin match can be adjusted to 75ohms. Have Fun, dave wa3gin
am I right in thinking that the general answer would be to make the 75-ohm feedline a multiple of a half-wavelength at the lowest operating frequency, and that the worst situation would be if the 75-
I sent a message directly to Micheal the originator of this thread but I see from many comments that one solution that always works was left out. I have tried to do the ingore the SWR approach of Ste
On the standard HF bands, one trick is to make the 75 ohm line a multiple of 1/2 WL on each band. A line that is a multiple of 1/2 WL on 40M will be 1 WL on 20M, 1.5 WL on 15M, 2 WL on 10M. A line th
I had the same question once. The SWR change is not great enough to warrant any stubs or anything. Just do not mix 50 ohm and 75 ohm coax. Also remember that your SWR meters are probably set up to re
Despite the theoretical difficulties, I have found the multiple 1/2 wavelengths solution to be highly practical in my situation, where the length of the 75-ohm CATV hardline is about 220 feet. My 2:1
In my installation, my single run of 75-ohm hardine is connected on either end to lengths of RG-213, and all my in-shack jumpers are 50-ohm. I think it makes sense, as Tom says, to not have more than
am I right in thinking that the general answer would be to make the 75-ohm feedline a multiple of a half-wavelength at the lowest operating frequency, and that the worst situation would be if the 75