Sirio Preformer 5000 Magnet Mount Antenna

[M0GVZ]

Can i use the rg8x the mini to do the bonding or is it not big enough

It'll do but RG213 braid would be better. Home depot sell braid earth straps but they're a bit too big for doing hood and trunk to body but are OK for doing cab and truck bed to chassis.

Try to keep it as flat as possible as its all about maximising the surface area.

 

[psycho]

It'll do but RG213 braid would be better. Home depot sell braid earth straps but they're a bit too big for doing hood and trunk to body but are OK for doing cab and truck bed to chassis.

Try to keep it as flat as possible as its all about maximising the surface area.

If you are going to use coax shield to bond body panels, you are wasting your time.
1" wide braid at a minimum and NO LONGER THAN 12".

 

[fourstringburn]

If you are going to use coax shield to bond body panels, you are wasting your time.
1" wide braid at a minimum and NO LONGER THAN 12".

Not so,

3ft. or less is perfectly fine. Real radio dealers sell them in lengths up to 3 ft. with terminal rings or in rolls for custom lengths.

Coax can work too. It is braided wire. I would pull out the center conductor. After all, the main purpose of it is to carry RF ground.

 

[psycho]

Not so,

3ft. or less is perfectly fine. Real radio dealers sell them in lengths up to 3 ft. with terminal rings or in rolls for custom lengths.

Coax can work too. It is braided wire. I would pull out the center conductor. After all, the main purpose of it is to carry RF ground.

What do I know....I only base my statements on first hand experience. I found through trial and error that if a ground strap is too long or has too little surface area, the RF won't see it.

 

[fourstringburn]

What do I know....I only base my statements on first hand experience. I found through trial and error that if a ground strap is too long or has too little surface area, the RF won't see it.

Actually your not far off track.

Since every mobile install is unique to itself, one shouldn't be too concerned with staying absolute on ground strap lengths when bonding a vehicle, but do keep them at the shortest practical lengths needed.

There is also common knowledge out there that suggests a ground strap more than 3 ft. can start to act as an antenna itself. That sounds plausible, but I haven't tried to see if it really does. Maybe the quote below suggest that since the fact if both inductive and capacitive reactances become equal, meaning a now resonant circuit, than the strap is now an antenna at the frequency the ground strap became resonant on and ceases to be an RF ground.


Here is a quote from the leading authoritative on HF installations.

Ground Straps

The first rule to follow about ground straps, is to keep them short! The rule of thumb is, 10 inches or less! And, there is a reason for why. A ground strap, like any piece of wire, has both inductive and capacitive reactances, which change with frequency. As the frequency increases, inductive reactance (in ohms) increases, but capacitive reactance (in ohms) decreases. When inductive reactance and capacitive reactance in any given piece of wire are equal, that wire will cease to be an RF ground.


Flat braided wire should be used for bonding, because RF flows on the surface rather than through the wire. Flat braid has more surface area for any given current carrying capacity, thus it provides less resistance to RF than an equivalent round wire. It also has more capacitive reactance which increases the self resonant point. Flat braid is also much more flexible and less likely to fail due to repeated flexing.


The shield from RG8 works well if the length of the strap is short (under 6 inches or so). Just take care when you strip off the outer jacket that you don't cut through the shield itself. Discard any that is corroded or discolored. Flatten it out by pulling it over a rounded surface. A large, round screwdriver shaft works well for this purpose.

 

[boomer111]

I recently purchased a Sirio 5000 performer, and like M0GVZ said, I purchased a Breedlove puck mount and drilled a hole right into my truck's sheetmetal roof skin and hard mounted it.

So how well does it work? Well, I havent gotten much air time with it, but I did talk to someone 5 miles away today, briefly. I wasn't able to get a signal report because I was driving and by the time I was parked and could watch the meter, he was gone.

Some say it works better than a Wilson 1000/5000 and I can see why. The whip on the Sirio is longer than the Wilson's. This means most likely there is less windings in the base coil. And the taller you can get and the less turns of coil = the more TX/RX it'll see.

About the only thing better might be a 108 whip, followed closely by a 102 whip.

Sadly with the DX cycle I'm thinking I just dont have enough power to make many contacts, as I am feeding a 4 watt carrier/10 watt modulation into a 4 pill amp with 2SC2879's inside. It needs a driver and I don't have one.

Also someone said this antenna works down to 12 meters....not so. I have checked mine and at best it has a flat SWR at 26.500 MHz, and at 28 MHz it's at 2.0:1. When I checked on 12 I think it was closer to 3.0:1....of course you could use an antenna tuner to make up for the last little bit, but not out of the box is it going to work.

A driver isn't going to help other than to create more signal on adjacent frequencies.

I recently purchased a Sirio 5000 performer, and like M0GVZ said, I purchased a Breedlove puck mount and drilled a hole right into my truck's sheetmetal roof skin and hard mounted it.

So how well does it work? Well, I havent gotten much air time with it, but I did talk to someone 5 miles away today, briefly. I wasn't able to get a signal report because I was driving and by the time I was parked and could watch the meter, he was gone.

Some say it works better than a Wilson 1000/5000 and I can see why. The whip on the Sirio is longer than the Wilson's. This means most likely there is less windings in the base coil. And the taller you can get and the less turns of coil = the more TX/RX it'll see.

About the only thing better might be a 108 whip, followed closely by a 102 whip.

Sadly with the DX cycle I'm thinking I just dont have enough power to make many contacts, as I am feeding a 4 watt carrier/10 watt modulation into a 4 pill amp with 2SC2879's inside. It needs a driver and I don't have one.

Also someone said this antenna works down to 12 meters....not so. I have checked mine and at best it has a flat SWR at 26.500 MHz, and at 28 MHz it's at 2.0:1. When I checked on 12 I think it was closer to 3.0:1....of course you could use an antenna tuner to make up for the last little bit, but not out of the box is it going to work.

Not true...a driver will just increase unwanted power on adjacent channels. Bleed over in simple terms.

You want the power to be on channel.

I run my 4 pill minus the driver that it came with. More power on channel now and less bleed over. I get good reports all the time and can talk to most stations that I can hear. Mobile with a Wilson 5000 mag.

 

[M0GVZ]

If you are going to use coax shield to bond body panels, you are wasting your time.

My antenna analyser disagrees. Both the feedpoint impedance and resonant frequency of the antenna changed as I was doing it proving that it was working.

 

[rabbiporkchop]

If interested I can explain making a shunt coil for a 1/4 wave antenna.

I'm interested

 

[Mudduckmobile]

I'm interested

I'm here to learn

 

[fourstringburn]

I'm here to learn

I thought I told you how already?

 

[Mudduckmobile]

I thought I told you how already?

Oh you did, and parts are on the way for new install. I just had to regroup, my wife had to go into the hospital, she had a kidney 14 months ago and has been fighting rejection, she was in for 5 days this time. All is getting better but its hard, she has had two transplants in the last 21 years, been fighting E.S.R. for 26 years.
Every chance I get I read to learn more.

 

[fourstringburn]

Oh you did, and parts are on the way for new install. I just had to regroup, my wife had to go into the hospital, she had a kidney 14 months ago and has been fighting rejection, she was in for 5 days this time. All is getting better but its hard, she has had two transplants in the last 21 years, been fighting E.S.R. for 26 years.
Every chance I get I read to learn more.

Wow, that's a lot to go through! I hope everything turns out OK for her!.

 

[Mudduckmobile]

Wow, that's a lot to go through! I hope everything turns out OK for her!.

Thank you...There is even more, My wife is 48. My wife has had 11 operation by the age of 3. She has had 1 Heart attack, 1 stroke, and Brest Cancer. She lost her kidneys to F.S.G.(s) at the age of 23, after fighting for 23 years. Hemo-Dialysis for 2 1/2 years, transplant (kidney), then Gallbladder removed, one adrenal gland removed, Then the heart attack, then 7 1/2 years late transplant removed as she got C=Dif. in the hospital, back on Hemo-Dialysis for 10 years, stroke, and then, 26 months ago she had all of her large intestine removed, at last 14 months ago she got the gift of life, a new kidney. And last Wednesday had another operation for 11 hours to try to fix an artery. When I hurt myself playing around doing thinks sometimes I bitch about how it hurts, then I look at the love of my life and remember I have NO problems, and god is good.
My wife will get better! She smiles all the time, and she loves god.

Wow, that's a lot to go through! I hope everything turns out OK for her!.

 

[undertaker]

Good luck and gods speed my friend....

 

[Mudduckmobile]

Good luck and gods speed my friend....

She thanks you !