Sirio Gainmaster

[Mudfoot]

A friend said he'd give me his Sirio Gainmaster that's about 8 months old if I replaced the cracked head on his old 98 Jeep Cherokee.

I have replaced a few, so guess who's getting the better end of the deal. He's mechanically challenged. I told him I would do it for nothing, but he insists on parting with it. He's not using it since he moved to an apartment and is now enjoying divorce proceedings.

It's really his kids Jeep so I am making him watch and help.

The Gainmaster has intrigued me some, but price turned me off. So now I can put this up and see if it lives up to the hype. Just have to sweat a little.

I'd pretty much help anyone work on an old Jeep for free.

 

[hayseed]

sirio

Been lookin at those....

Hurrry up and get it up so you can give a report....

 

[Marconi]

m42duster, you didn't ask for help, but I'll give you one piece of advice that I experienced using my Gain Master. Try and get it up above 20' if you can. I found the match on mine responded badly at 11' feet, and when I raised it to 18' the problem was still pretty much there. At 20' the match gave a normal response.

I can not say however, that you will be able to tell this if you're just using an in-line SWR meter. Notice my bandwidth chart, I did a curve using both an analyzer and an in-line meter, and the SWR bandwidth curve does not reflect this match going out of sorts.

Will this issue make any difference to performance, I have no idea, but lots of guy's claim that the match must be 1.10:1 or better in order to work best. The analyzer curve at 56' is about normal for all elevations above 20' feet at my location, and all anomalies noted in the irregular bandwidth curve were at least lower rather than higher. I just feel uncomfortable when I see a match get crazy.

Others have made similar observations.

Your mileage may vary.

 

[Mudfoot]

It has to occupy my 38' mast pipe on side of my house. Presently, my 2 meter omni resides there. Once installed, the base will be around 8-9' above my shingled roofline.

I live on a corner lot and our neighbors house is about 6' away. They have a slate roof with metal ridge caps and a gutter that will be close to 20 feet away and about 13-15' below. My 80 meter wire is tied off about 5' below and the insulator is 5' away. It won't be an optimal install, but will have to do.

I had an old 5/8 wave, an Antron and an IMAX on the same pole and had decent results. I have been reading where this antenna likes plenty of free space below it. I think it said to try to get 3 meters above the roof or nearby wall. I'll be close to that.

I am hoping it will be okay, but have to wait and see. I move slow anymore and will try to get it in the air within a week or two.

 

[Marconi]

Sounds like you've got a plan and a lot going on. Keep us posted, OK?

 

[Needle Bender]

That's awful close to many things. You might not like it as much as the old 5/8 or Imax.
They typically don't seem to show much performance unless quite high and in clear sky.
When is it going up?
How long has it been since you had the Imax or 5/8 up? Will you remember how they performed in comparison?

 

[Zman]

Just dont try to run much juice into it! LOL they only take 500 watts or so.. My phantom would melt that antenna in no time flat.

 

[Needle Bender]

Just dont try to run much juice into it! LOL they only take 500 watts or so.. My phantom would melt that antenna in no time flat.

About a year ago Shockwave posted a 1500w mod for it here.

 

[Mudfoot]

That's awful close to many things. You might not like it as much as the old 5/8 or Imax.
They typically don't seem to show much performance unless quite high and in clear sky.
When is it going up?
How long has it been since you had the Imax or 5/8 up? Will you remember how they performed in comparison?

I took the IMAX down about a year ago and replaced it with a 13B2, then I replaced that with a 2 meter omni about 3 months ago. I have a new spot for the omni. I just don't work much 2 meters. The other ground planes that were up in the past did pretty good.

I know it's not optimal, but it's what I have and what I have to put up with. I am working on the Jeep this weekend, but will likely have a sore back, knees, shoulders, hands and knuckles for a few days that will delay installing the vertical. pain getting old.

 

[Mudfoot]

Here's a pic when the 13B2 was up. I was thinking I may slip a 10' Rat Shack 1.25" TV mast down inside the top section about three feet. It would give me another 7' height and should be stable enough to hold the Gainmaster.


Input???

 

[Needle Bender]

Every little bit definitely helps with the GM, especially if it gets it that much higher above the HF wire.

It's a fickle biaatch, but...

Up and alone in it's own clear sky,
it really provides a performance 'High'.