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Sirio 827 base antennae issue

Dark Star

Active Member
Jan 24, 2020
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Hi all, not even sure if there is an issue or not with this antenae. After assembling this antennae I checked for any shorts. I was getting full continuity between center pin and SO-239 at antennae base. I called Sirio support and was told this was normal because this is a DC grounded antennae. Ok. I was not familiar such a thing existed. In my experience continuity between pin and shield is not a good thing but I was assured from Sirio that this was the way this antennae works. I attached the coax and checked my swr and what do ya know...it was actually very good, about 1.2:1. Output from my system seemed fine with very little reflected wattage. Thought I would be ok but no. I was using my Texas Star 500V today and all of a sudden output from the amplifier dropped to almost nothing. Can't see any visually cooked components but it's definitely smoked. I can smell it and no output. Could this have been caused because of the "designed shorting" of these dc grounded antennaes or maybe something else. Any experience with this kind is thing? Oh and before anyone said it, no I was not overdriving or overvolting this amp. 3 watts input @ w 14.0V from a Megawatt supply. Thanks for any help. 73
 

NightOwl3261

Well-Known Member
Jul 24, 2020
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No DC grounded will not smoke an amp.
A test between the center pin and ground will basically show what you seen or what some would call a DEAD SHORT" The length measurements given by sirio are relative starting point to get you close to a low SWR on 11 meters with some tweaking. There is no relationship between a DC grounded antenna and your amp getting smoked. Sorry its a bad day when your Texas Star let's out smoke. I feel your pain

if this is a late model Texas star, non Toshiba pilled amp (DEI or HG) They are very swr sensitive (nothing over 1.3:1) Maybe your SWR was on the bitter edge of SWR and maybe your swr meter was not accurate enough to get an accurate reading. That would be my guess. Above 1.3:1 and TS went boom...
 
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Dark Star

Active Member
Jan 24, 2020
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You could very well be correct. Swr is no higher than 1.2:1 but when I turn on the amp it goes up a bit to 1.4:1 or so, at the highest. However when modulating it goes back down to 1.2:1 or below. I'm using a Palstar cross meter and it reads +/- 5 watts to my friends Bird meter so I know it's pretty close. Damn a Texas Star can't handle a 1.3:1? That's ridiculous. Any decent amp or radio should be able to handle at least 1.5:1 you would think. What a piece of junk if that's the case. Thanks for the feedback.
 

Justme

Sr. Member
Jan 28, 2008
591
722
103
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The Netherlands
I consider any amp that cannot handle a 1:3 SWR as crap.
at least there should be a fold back circuit in that amp to protect the amp.

My FT 991A as well FT 2000-D 200 watt radio both can handle swr from 1:3 or higher folding back power to protect the final FET's.
My old Heathkit SB-1000 will laugh at a SWR of 1:3.
But then i never drive it to the max.

Sorry for your loss there though, but that happens with P.A's that run on max power without decent protection.
But then they would cost more...
 

bob85

Supporting Member
Mar 30, 2005
3,478
1,436
173
england
Never heard of anybody having issues with a new sirio 827,

The common issue with them is that short you are worried about going open circuit & blowing your amplifier once the weather has had time to work on the dissimilar metals & sintered hubs that go none conductive,

first signs is usually your rx intermittently dropping out when you unkey & can't hear anybody,

827's have killed more amps than gain-masters round here & its always the same fault,
open circuit on the coil connections or the top hub loses its connection to the radiator,

a couple of <100w locals have had no issues for 10+ years with their 827 but that's rare in this area,

nobody smoked an amp with a new 827, but a few have smoked 4 pills with new gainmasters not watching the vswr on long overs.
 

Dark Star

Active Member
Jan 24, 2020
72
68
28
50
Hopefully my 827 does not develop the open loop issue in the future. The odd thing is that I did notice that the reflected wattage would jump quite a bit as I climbed closer to the upper part of the band. But without the amp on there was not much difference at all in reflected power. As a test I hooked up my 350HDV to the exact same system that I was running the 500 on (yeah I'm brave...or stupid) but seriously, no difference at all with this amp on reflected watts between low end and high end of band. I truthfully feel I got a poorly made 500 from the factory. Whether it's poorly matched pills or something else, I am leaning toward the problem being this particular amp. Well it's going back out to Cali for Mike at Texas Star to look at and decide at this point. Bummer though, it takes them a LONG time to repair stuff right now. So no base amp for the rest of the summer at least.
 

Dark Star

Active Member
Jan 24, 2020
72
68
28
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So it's been awhile since the last post on this situation. Well I'm convinced it's just that Texas Star is now total crap. Steer clear of these amps as they are now total crap. I have alot of respect for Mike and I know he knows these amps but he is in denial just as Texas Star is as a company that their amplifiers are now total shit. They cannot perform on anything but a dummy load. I've spent a ton of money paying for them replacing transistors, even paid extra for HG transistors opposed to their usual shit DEI offered junk. Well guess what... both DEI and HG will not perform with their old circuit which is designed for Toshiba pills. They will not admit that their amplifiers suck with anything but Toshibas installed. My advice is to avoid any modern Texas Star like a crazy monkey plague!
 
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Greg T

945 (Jazz Singer) Upper Peninsula of Michigan
Sep 18, 2014
648
890
103
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Escanaba, Michigan
So it's been awhile since the last post on this situation. Well I'm convinced it's just that Texas Star is now total crap. Steer clear of these amps as they are now total crap. I have alot of respect for Mike and I know he knows these amps but he is in denial just as Texas Star is as a company that their amplifiers are now total shit. They cannot perform on anything but a dummy load. I've spent a ton of money paying for them replacing transistors, even paid extra for HG transistors opposed to their usual shit DEI offered junk. Well guess what... both DEI and HG will not perform with their old circuit which is designed for Toshiba pills. They will not admit that their amplifiers suck with anything but Toshibas installed. My advice is to avoid any modern Texas Star like a crazy monkey plague!
I've been running the HG flavored 500 for about three years now. No issues at all. With the power wire upgrade I'm getting a solid 600+ out of it and excellent audio reports. What you don't want to do is over drive it.
 

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