PolyPhaser Hi SWR

[flintstone mop]

Hello All,
I have discovered a a slightly high SWR going through my lightning protection. They are PolyPhaser and are capable of a wide freq range and can handle 2KW at the HFfreqs.
My Coax is flat from the "tower" to the shack. When the protectors are in place I see a slight increase in SWR, about 1.5:1, as I increase freq to 15M the humps and bumps in SWR begin reaching almost 1.7:1. And a little above THAT near 10M.
I'm sweeping these freqs with my MFJ 2590.
Are the protectors shot? Both do the  same thing. One protects the shack from lightning from the Yagi and one for the beverage antenna.

Thanks for any ideas.

Fred

[K1JJ]

Fred,

I don't know what the Polyphasers should show for an swr curve, but you would think they should be more transparent than that.  I would look up the Polyphaser info on the web. It will surely show the insertion swr and is probably down around 1.1:1.   Check it out  or just call the company and axe them.


Be sure you have installed them correctly so you don't have an impedance bump. Try to simulate a 50 ohm coax (relation to ground) through the installation of the parts.

Maybe some guys here have experience with them too and can advise.

T

[Steve - WB3HUZ]

Take the Polyphaser out of line and connect them to a 50 Ohm dummy load. Then sweep them.

Hello All,
I have discovered a a slightly high SWR going through my lightning protection. They are PolyPhaser and are capable of a wide freq range and can handle 2KW at the HFfreqs.
My Coax is flat from the "tower" to the shack. When the protectors are in place I see a slight increase in SWR, about 1.5:1, as I increase freq to 15M the humps and bumps in SWR begin reaching almost 1.7:1. And a little above THAT near 10M.
I'm sweeping these freqs with my MFJ 2590.
Are the protectors shot? Both do the  same thing. One protects the shack from lightning from the Yagi and one for the beverage antenna.

Thanks for any ideas.

Fred

[W1ATR]

Sounds like it's all done Fred. Mine started to show a slight swr then I finally killed it all together with a kw of cw. When it died, I queried Poly about it and didn't rx a response. So a little googling turned up a long post on eham about the same problem with these.

I decided that this tiny little box with a cap inside is not going to stop a Terawatt of energy that just just jumped a mile thru open air, so I went back to the tried and true method of knife switching them to ground when I hear the boom booms coming.

[K5UJ]

Sounds like it's all done Fred. Mine started to show a slight swr then I finally killed it all together with a kw of cw. When it died, I queried Poly about it and didn't rx a response. So a little googling turned up a long post on eham about the same problem with these.

I decided that this tiny little box with a cap inside is not going to stop a Terawatt of energy that just just jumped a mile thru open air, so I went back to the tried and true method of knife switching them to ground when I hear the boom booms coming.

Same here Fred; I never fooled with that stuff; I just pull the open wire feeds out of the banana jacks outside when I am away from home or hear the storm static.  Ditto for the vertical coax lines--disconnect them outside.  Gear inside defaults to being unplugged in the summer when I'm QRT.  No damage so far knock on wood.  I even dropped my ARRL rig insurance.
If u running big old tube BA gear you may have even less to worry about compared to guys like me with the surface mount s.s. stuff.
Rob

[flintstone mop]

Well, I guess I'll start knocking on wood too. And bypass the PolyPhasers.
I was just going through the drill of trying to protect from lightning .
I always disconnect any way even during the Winter Time.


Fred

[K5UJ]

Well, I guess I'll start knocking on wood too. And bypass the PolyPhasers.
I was just going through the drill of trying to protect from lightning .
I always disconnect any way even during the Winter Time.


Fred

Good idea.  I have a bad habit of relaxing from mid-December through February because around here the temperature is below freezing but then we had a dang night-time thunderstorm in mid-January last year.  I couldn't frigging believe it, had to run around in the snow in the dark shutting everything down. 

[ka3zlr]

Fred, don't mean to butt in on your thread can you bury your coax...?..it'sa cheap effect lightning arrestor for the most part it doesn't like to bend so with yer coax coming straight down and bendin to the right or left lightning will blow straight through happened here with me...I bury all coax and hit my antennas... I have so many... .hi..hi at right angle up...

73
Jack.

[W8BAC/Mobile]

Hi Fred,
I have used the Polly Phasor's in the past and had gool luck with them until I picked up a few at a fest. The fest polly's showed a high vswr and had me stumped until I looked up the part number and found they had been made for the FM broadcast band. They swept fine on the bcb but fell off at about 70 MHz. If your not sure, check the p/n. They are frequency sensitive.

Mike

[nq5t]

Fred, don't mean to butt in on your thread can you bury your coax...?..it'sa cheap effect lightning arrestor for the most part it doesn't like to bend so with yer coax coming straight down and bendin to the right or left lightning will blow straight through happened here with me...I bury all coax and hit my antennas... I have so many... .hi..hi at right angle up...

Something I've seen suggested (and have thought about myself, haven't done anything with it) is a long (around 10+ ft or so) piece of copper pipe on the surface, bonded to maybe 3 ground rods with the cables fished through it.  I think someone mentioned that around here at one time, but I'm getting too old to remember anything past last week ;-)

Grant/NQ5T

[flintstone mop]

Jack the coax and rotator wires are in conduit coming to the shack.
Mike, they were pretty wide band. 1.5mhz to 30 2kw rating and there were higher vhf freqs in the specs also.
I bypassed them and getting closer to be able to compete with Tom VU and his stack. I'm trying to get rid of all losses and SWR's.

Fred

[K1JJ]

I bypassed them and getting closer to be able to compete with Tom VU and his stack.

Here's a stack I'd like to compete for...

T

[K9PNP]

I have seen the polys work.  The service I used to work for took a direct hit on the VHF hi-band antenna.  Totaled the fiberglass gain antenna and fried some of the LMR-1200, but the poly saved the base station.  They made fun of me when I speced them, but looks like saved them about $10K.    Personally, I unhook all the antenna feeds and shut down the AC power to the rigs [1 breaker now] when I go QRT.  Like other have said, this is good insurance.  Would not want to have to replace the S-line, the Multi-Elmac set, and all the other BAs.

[Jim, W5JO]

I am curious as to the number of hits the Polyphase absorbs before mandatory replacement?  Some surge suppressors have a spec for that some don't.  A friend in South Texas had them on his line and after a year of frequent thunderstorms they went bad. 

After failure they burned the coax to the point it required replacement.  Predicting lightning is like herding cats, no one knows where it will go.

[Mike/W8BAC]

Fred,

The PolyPhaser is an extremely simple device. A "Gas" tube (misnomer, Vacuum Tube) from the center conductor of the coax which offers a luscious ground path to surge DC and a happy path from the RF transmitter to an antenna.  I'm no RF engineer but I can't imagine any sort of failure mode in that tube that could change the SWR.

Jack,

Putting your coax underground and expecting that to stop lightening from entering the shack would mean you have more than your coax buried in the sand.

Mike

[ka3zlr]

It is One thing I do even though it's considered a Placebo by some, But down through the years of strikes I found I do not Trust PolyPhaser anything, and I use my own methods Thanks you very much.

73
Jack.