Polyphaser

[jazzboypro]

Hello all,

I will soon be installing a loop antenna (W6LVP) and a discone antenna (Diamond D-130N) both antennas will be connected to mi IC-R8600. i am looking at Polyphaser for an RF surge protector. I see that they have many models. I have 2 questions.

1- Apart from making sure they have the right connectors is there something else i should look for ?
2- Do i need one for each antenna or can both antennas use the same surge protector ?

Thanks
73
VA2FCS

 

[k7ng]

I assume that you will be using a splitter or multicoupler, or using different antenna inputs? You shouldn't just use a T connector to combine two or more antennas to a single antenna port on the radio. Thusly you really should put your surge protectors as close to where the coax comes into your house as you can, and one antenna per protector. You want as short, direct, straight connection to ground as you can get, preferably using flat braid or a flat metal strip. Putting a single surge protector behind a splitter or multicoupler, in case of a high energy event... the coupler will protect the surge protector by blowing up first.

For receiving purposes only, the power rating of a surge protector matters... you won't want one rated for kilowatts - that's transmit power up the pipe, not energy the protector can block, and the higher power rating, the higher surge it takes to trigger the protection device. The 'let-through' energy of a surge protector is an indicator of what will hit the receiver after the protector does its job. The lower the better.

Frequency of operation is of interest too. Are you planning to be listening below 10 MHz? Below 50 MHz? Above 1 GHz?

Are you going to be using a preamplifier powered thru the coax cable? Some protectors block DC, others feed DC thru.

With that information in hand, perhaps I or someone else can offer suggestions, or using those parameters, you can decide on your own.

I'm willing to try to help.

 

[vagrant]

1. Pay attention to the frequency coverage for each one.
2. I would use two and connect the antennas to their respective ports on the back of the radio. I would not use a diplexer as that receiver has two ports.

 

[k7ng]

I'm not familiar with the R-8600, I should have guessed it had two antenna ports.

Look at Polyphaser's 'GTT' products and see if there's something there that might suit your needs.

I don't work for them or sell their products. I've used a lot of them, is all.

 

[mmckenna]

I will soon be installing a loop antenna (W6LVP) and a discone antenna (Diamond D-130N) both antennas will be connected to mi IC-R8600. i am looking at Polyphaser for an RF surge protector. I see that they have many models. I have 2 questions.

I have an AOR-2300 remote receiver at one of my high sites. I have an end fed wire connected to the HF antenna port and a Telewave discone connected to the VHF/UHF port.
I'm using Polyphaser GT-NFF-AL on both antennas. They've been up there many years, no issues.

Those will work fine for both yout antennas.

Where you would need to pay attention is for the loop antenna. Since it's an 'active' antenna, it requires power fed from your shack via the coax. Some lightning protectors will not pass DC voltage. However, the GT-NFF-AL -will- pass power, so you can feed your loop the power it needs.

If you decide to go with a different brand/model, just make sure it includes a "DC Pass" capability. You'll often find those used for GPS antennas where it requires 5vdc fed up from the receiver.

 

[jazzboypro]

I assume that you will be using a splitter or multicoupler, or using different antenna inputs? You shouldn't just use a T connector to combine two or more antennas to a single antenna port on the radio. Thusly you really should put your surge protectors as close to where the coax comes into your house as you can, and one antenna per protector. You want as short, direct, straight connection to ground as you can get, preferably using flat braid or a flat metal strip. Putting a single surge protector behind a splitter or multicoupler, in case of a high energy event... the coupler will protect the surge protector by blowing up first.

For receiving purposes only, the power rating of a surge protector matters... you won't want one rated for kilowatts - that's transmit power up the pipe, not energy the protector can block, and the higher power rating, the higher surge it takes to trigger the protection device. The 'let-through' energy of a surge protector is an indicator of what will hit the receiver after the protector does its job. The lower the better.

Frequency of operation is of interest too. Are you planning to be listening below 10 MHz? Below 50 MHz? Above 1 GHz?

Are you going to be using a preamplifier powered thru the coax cable? Some protectors block DC, others feed DC thru.

With that information in hand, perhaps I or someone else can offer suggestions, or using those parameters, you can decide on your own.

I'm willing to try to help.

I will not use a splitter or multicoupler. The loop and discone have their own ports on the back of the radio. As for the frequencies, the loop will be used for everything below 30 MHz and the discone will be used fot the rest (as much as possible). The loop is an active loop so yes DC will need to to fed thru the coax. Putting the protector near where the coax enters the house will not be a problem. At this point i guess that 2 surge protectors is the way to go. I just need to determine the right model.

 

[jazzboypro]

I have an AOR-2300 remote receiver at one of my high sites. I have an end fed wire connected to the HF antenna port and a Telewave discone connected to the VHF/UHF port.
I'm using Polyphaser GT-NFF-AL on both antennas. They've been up there many years, no issues.

Those will work fine for both yout antennas.

Where you would need to pay attention is for the loop antenna. Since it's an 'active' antenna, it requires power fed from your shack via the coax. Some lightning protectors will not pass DC voltage. However, the GT-NFF-AL -will- pass power, so you can feed your loop the power it needs.

If you decide to go with a different brand/model, just make sure it includes a "DC Pass" capability. You'll often find those used for GPS antennas where it requires 5vdc fed up from the receiver.

Thanks for the suggestion, i will definitely look into this model.

 

[prcguy]

For HF I've been using gas tube lightning arrestors from Alpha Delta and for VHF/UHF and up Polyphaser. The Alpha Delta and most other gas tube types will easily pass 12V DC for the active antenna.

Since both of your antennas are very small its unlikely you would ever have an EMP event from a close lightning strike. That is almost always from a long wire type antenna that will pick up thousands of volts from a nearby strike. For your type antennas you could get away with a simple grounding block in each coax path and that would be NEC legal. My thought is you will never survive a direct strike and probably never have much induced voltage from a nearby strike, so grounding to NEC should be sufficient.

I also forget your not in the US and NEC doesn't apply but Canada should have similar regulations.

 

[jazzboypro]

For HF I've been using gas tube lightning arrestors from Alpha Delta and for VHF/UHF and up Polyphaser. The Alpha Delta and most other gas tube types will easily pass 12V DC for the active antenna.

Since both of your antennas are very small its unlikely you would ever have an EMP event from a close lightning strike. That is almost always from a long wire type antenna that will pick up thousands of volts from a nearby strike. For your type antennas you could get away with a simple grounding block in each coax path and that would be NEC legal. My thought is you will never survive a direct strike and probably never have much induced voltage from a nearby strike, so grounding to NEC should be sufficient.

I also forget your not in the US and NEC doesn't apply but Canada should have similar regulations.

Any particular reason why you use Alpha Delta for HF and Polyphaser for VHF/UHF ?

 

[prcguy]

Most of the new old stock Polyphasers I bought cheap are rated for 125MHz to 1GHZ and not for HF, plus they don't pass DC. I also got a deal on a big lot of Alpha Delta units that were rated to 200MHz, not good enough for my UHF repeaters but fine for HF and they pass DC. In my case it was more price driven buying in qty. If I had to buy new units at retail I would probably buy Polyphaser for everything.

Any particular reason why you use Alpha Delta for HF and Polyphaser for VHF/UHF ?

 

[jazzboypro]

Most of the new old stock Polyphasers I bought cheap are rated for 125MHz to 1GHZ and not for HF, plus they don't pass DC. I also got a deal on a big lot of Alpha Delta units that were rated to 200MHz, not good enough for my UHF repeaters but fine for HF and they pass DC. In my case it was more price driven buying in qty. If I had to buy new units at retail I would probably buy Polyphaser for everything.

Thanks for the info. I trhink i'm missing a step here. I understand that surge protector does not ground the feed line. So in order to ground the feed line am I suppose to connect the body of the surge protector to the ground rod ?

 

[jazzboypro]

Sorry for my last post, i looked at the polyphaser installation documentation and found my answer.