Copper Talk » Ask The Tech » Amplifiers » Texas Star 667V--Is Output the same on both AM & SSB ??? « Previous Next »

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Foxhunter
Junior Member
Username: Foxhunter

Post Number: 19
Registered: 4-2008


Posted on Friday, June 13, 2008 - 10:46 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hi I have a question(s) this time about a Texas Star 667V and I really read thru as much of old Copper Forum posts as I could first hoping to find an answer before posting.

1) Firstly---is the amplifier's output the same on AM as it is on SSB? I've read here in old posts, to expect about 500W (+/-) with this amp (with "normal" voltage levels and input).

2) But, will I see an increase on SSB or will I see a decrease on AM---or will the output levels be the same?

3)One more question---The amps specs at Texas Star's data sheet lists inputs of either 4W or 20W. Is that telling me those specific inputs can be BETWEEN 4W-20W, OR, are the input levels somehow "fixed" internally to accept one drive level or the other? Or does this amp basically has a variable input drive anywhere between 4W-20W that I can simply change with the radio's variable output?

Please I could use the answers to these questions very much "before something awful happens" as I am not very familiar with this (seemingly popular) make of amp. Thanks---Foxhunter

***One more thing about the input. If the either input drive-level is used, Should I set the dead key lower to allow for PEP "swing" so as not to overdrive the amp??
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Patzerozero
Senior Member
Username: Patzerozero

Post Number: 4285
Registered: 7-2004


Posted on Saturday, June 14, 2008 - 1:11 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

1. firstly, it depends on how the RADIO is tuned.
2. secondly, see firstly
3. thirdly, whoever wrote texas stars specs page musta got hit in the head when i threw my galaxy out the window & got a bit confused

"before something awful happens" and to answer 'One more question' and '***One more thing about the input'-the dx667v is a 1x4 amp, or 1-2sc2290 transistor driving 4-2sc2879's, it has its own 'driver' built in & requires LOW input. to 'set up' this or ANY amp, you need to know the output of the transistors, less driver stage, which in this case is 4 x 120 watts PEP. therefore, you should be able see roughly 480 watts PEP, and 25% of that, or 120 watts in carrier/dead key on AM. to set AM, if the radio has an external rf power control, turn it down to minimum, if not, open it up & turn AM power VR down. turn mic gain to zero. turn amp on, key radio & turn up variable power til amp shows 120 watts dead key. then, turn mic gain up & talk til you see around 480 watts PEP(swing). if it's 50 or so watts LESS, not much you can do about it, if it's much more then 550 watts PEP, get some audio checks from people you trust. you may need to turn mic gain down or recheck SWR. once you're happy with that, you can try to increase radio power til amp shows 150 watts carrier-check for heat. you may even be able to go to 175 dead key. always make sure swing is 3-4 times the carrier, so if you get 175 carrier, & amp doesn't get too hot, make sure PEP is around 550-600. again check audio quality. for SSB, turn mic gain to zero, turn amp on with ssb delay switch, and talk. turn mic gain up til that magic 4x120 or 480 watts of swing exists. again, if you fall a bit short, oh well, if it goes much over 500, get audio checks! there is no problem if AM out is more then SSB out, though if the radio is tuned right, the difference is probably less then 100 watts, and AM swing just might be HIGHER then SSB. don't worry about it!
some people claim far higher, forget it, it's probably false due to a match problem. besides, if you get 400 & someone else gets 500, equal antennas, nobody will ever know!
always set up an amp as above, then you won't be at as much risk of something awful happening! and FORGET about EVERYBODY'S claim of output, and texas stars input suggestions!
texas star has always made decent products & i would ALWAYS recommend them!
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Hotwire
Senior Member
Username: Hotwire

Post Number: 2510
Registered: 1-2005


Posted on Saturday, June 14, 2008 - 3:54 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Pat hit the nail on the head. That's how I've been running my Texas Stars for years now with great audio reports and performance.
I have noticed that when in SSB mode the TS amp pulls much harder on my alternator so I tend to lower mic gain a lot. Loud and proud is ok on AM but awful in SSB modes.
Always a good idea to add a fan to those amps. Seems like the heat sink is a bit restricted by the face plate.
Great amps, besides a couple of keying transistors gone bad on mine I too will always recommend them!
KEEP IT REAL!
Kenny
cef491(27.115lsb)
2sf491(27.555usb)
Indiana
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Mdiver
Advanced Member
Username: Mdiver

Post Number: 593
Registered: 11-2003
Posted on Saturday, June 14, 2008 - 9:31 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I think I will bookmark this page..
CEF-252
Steve Northern California
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Patzerozero
Senior Member
Username: Patzerozero

Post Number: 4287
Registered: 7-2004


Posted on Saturday, June 14, 2008 - 9:56 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

wassamatta, steve, you don't like my use of the word 'secondly'
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Foxhunter
Junior Member
Username: Foxhunter

Post Number: 20
Registered: 4-2008


Posted on Sunday, June 15, 2008 - 7:03 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

"Secondly....see Firstly" HeeHee----Pat I knew you were a character the first time I saw your avatar. Listen I want to thank you the input was much-needed and appreciated. The Texas Star amp-maker should have you write an instruction manual for their unit(s). Perhaps you should? I've read many of your prior posts and knew I'd get good advice. Pssst------I heard Galaxy want's your input on writing their manuals.....
Also Pat I saw some pic's you'd posted somewhere it looks like you have a choice collection going (they were assembled on a wire rack. Also thank you to hotwire for the confirmation and I'd been reading some of the older posts here about the fan-kit installation for the amp. I took a chance awhile back and did my own fan-install on an old Palomar to keep the tubes cooler and it worked out well, I used 2 fans that were surplus from a PC.
"Lastly"----Thank You-------Foxhunter
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Patzerozero
Senior Member
Username: Patzerozero

Post Number: 4291
Registered: 7-2004


Posted on Thursday, June 19, 2008 - 6:55 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

'I heard Galaxy want's your input on writing their manuals'-'before removing radio from packaging, place in 1400° furnace for 30 minutes, or until ash pile no longer shrinks....

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