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Good reception poor transmit

Duckodb

New Member
Apr 15, 2023
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I guess this is the right place to post this question. I recently bought a Sirio M-400 and got it put up, the mast is around 18’ and it’s strapped to the side of my house, idk the exact overall height but it’s well above the peak of the roof. I’ve got a Stryker 955 hooked to it on 14.8 volts from a power supply in my living room. This 955 was previously in my truck and was talking on lsb 16 miles easy to my other truck at 14.0 volts, now since it’s in the house it’s not talking 5 miles. SWRs are down around 1.2 on 40 and around 1.3 on 1 and it receives really good. My wife was coming home from work earlier and she was putting my meter over to 9 from 12 miles away but couldn’t hear me till she was 4 or 5 away. Im in PA and Ive been hearing people from Canada, Michigan, Texas and even Washington state on 38lsb. I’m using Wilson coax and steel RCA antenna mast all the way into the ground. This is my first time with a base antenna so any thoughts on why I receive good but have bad transmit are appreciated. I’ve also tried different mics with no change in results. I tried my RCI 99N1 which is hooked up now and it’s about the same.
 

Sounds strange, how old is the coax and how long is it?
It’s actually 2 18’ Wilson mini 8s so 36ft
and they’re both a week old same as the antenna and mast. Best I can figure it’s about 32-33’ to the tip top of the antenna. Strange that the same radio in my truck with a Hustler hq27 55” antenna sitting in my driveway would talk at least 16 miles which is the furthest we talked but would’ve easily gone another mile or two. I thought you get a base antenna put it together tune it to a low swr and mount it as high as you could and you’d be talking further. I turned in our shop at work this morning which is 5.1 miles away and I could barely hear my wife talking on the one in the living room and she said i sounded like i was in our driveway.
 
It’s poor on transmit because it is a 1/4 wave antenna. Today's standards call for at least a 5/8 wave for optimum TX take off angle. Your antenna basically transmits sideways. Sure it RX's well because of those 3 radials at the bottom.
Well what’s a good 5/8 wave 11 meter antenna to get? I saw a Sirio GPE 27 that says it’s 5/8 and it’s only about $95. Anybody have any experience with those? If it would get out about 20 miles just for local talking is all I really care about.
 
Lets take a step back here.
I have a local buddy who has the M400 but his is like 50ft off the ground to the mount base of the antenna. Yours if I read correctly is 16ft to the bottom of the antenna mount. Most ranch homes are 16ft from ground to roof peak. Thats not high enough for that antenna to work its best. Most antennas including 5/8 wave antennas work best at 30ft from the ground up to the antenna mounting plate.
I don't know your situation or surrounding homes/trees/etc. Would you mind posting a pic of how you have it setup?
 
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Lets take a step back here.
I have a local buddy who has the M400 but his is like 50ft off the ground to the mount base of the antenna. Yours if I read correctly is 16ft to the bottom of the antenna mount. Most ranch homes are 16ft from ground to roof peak. Thats not high enough for that antenna to work its best. Most antennas including 5/8 wave antennas work best at 30ft from the ground up to the antenna mounting plate.
I don't know your situation or surrounding homes/trees/etc. Would you mind posting a pic of how you have it setup?
Mines probably about 23’ to where the coax screws on , an 18ft coax is at least 5 feet above the ground where it comes down the mast.
 
You haven't mentioned what the mast is made of, hopefully, it's a metal pipe.

Do you have your base setup grounded? If not try connecting a ground cable from the mast to a water pipe that is metal and not plastic, or to a ground rod, this would at least add to your ground plane.

It would help if you got the antenna a lot higher (above the ground) before you decide to get a 5/8 wave antenna that may also have to be higher to get better performance, but the system should be grounded first.
 
You haven't mentioned what the mast is made of, hopefully, it's a metal pipe.

Do you have your base setup grounded? If not try connecting a ground cable from the mast to a water pipe that is metal and not plastic, or to a ground rod, this would at least add to your ground plane.

It would help if you got the antenna a lot higher (above the ground) before you decide to get a 5/8 wave antenna that may also have to be higher to get better performance, but the system should be grounded first.
Yes in the first post I said steel rca antenna mast. To the base of the antenna where the coax screws on it’s about 23 feet to the ground.
 
Antenna should be insulated from mast. We don't want it to be a part of antenna system, so the coax. That's why we use choke baluns under antenna feed point.
Mike
I’ve got a piece of steel pipe stuck in the bottom of the antenna and the coax runs down through it, it’s about 5 ft long then the steel mast is attached to that pipe with about 5 clamps so it is metal to metal. Should I have used a piece of electrical conduit pipe into the base of the antenna then clamped it to the mast? Then how would it be grounded?
 
Its poor on transmit because it is a 1/4 wave antenna. Today's standards call for at least a 5/8 wave for optimum TX take off angle. Your antenna basically transmits sideways. Sure it RX's well because of those 3 radials at the bottom.
An antenna should perform the same on RX as it does on TX. Look up "antenna reciprocity".The take off angle is the same for RX as it is for TX. Those three radials on the bottom should NOT make a difference on RX versus TX.
 
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