| Author |
Message |
    
Sg569
Member
Username: Sg569
Post Number: 61
Registered: 12-2004
| | Posted on Wednesday, January 26, 2005 - 12:59 pm: | 
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Gentlemen,
What would be the pros and cons for running two 2sc1969 tranistors for finals instead of running one 2sc2166, and one 2sc1969???
Any Thoughts???
Thanks,
sg569 |
Bruce
Senior Member
Username: Bruce
Post Number: 2136
Registered: 9-2003
| | Posted on Thursday, January 27, 2005 - 4:59 am: |
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You get twice the power of one ........ the HTX-10 / MAG-257 us them it works fine. |
Grts
New member
Username: Grts
Post Number: 3
Registered: 12-2002
| | Posted on Thursday, January 27, 2005 - 10:32 am: |
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Peak power will not be doubled. The cost and time involved is not worth the extra 5-7 watts pep power you would gain. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 175
Registered: 9-2004
| | Posted on Thursday, January 27, 2005 - 4:09 pm: |
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i think you guys are misreading his post.
sg569, your radio only has one "final" in it. the 2sc2166 is the driver, or "exciter". it amplifies your signal from the milliwatt range up to 1 watt or more which is what the 2sc1969 needs to perform properly. your radio's transmitter is not designed to use a 2sc1969 as a driver and you most likely wont be able to bias it properly.
TO EVERYONE WHO THINKS THAT SIMPLY REPLACING THE FINAL IN YOUR RADIO WILL MAKE A NOTICABLE DIFFERENCE: do an little experiment for me. next time you are on the radio talking with someone you know will give you an honest answer; do the following. key up your mic and turn your AM POWER slowly all the way down and then all the way up, and then back to wherever you usually set it.(you dont leave it all the way up do you?) dont tell your friend what you are doing and ask him/her what the carrier looked like. the answers should put your myths to rest.
matt |
Red
New member
Username: Red
Post Number: 1
Registered: 1-2005
| | Posted on Saturday, February 05, 2005 - 7:54 am: |
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Heres a question for the techs. I have a TrippLite PS-40 powering a Galaxy DX-959 and a Little Red Hooker 250 box. If I hook up two 3 1/2 computer fans to this power supply with a switch in line and fans on. When I key up with the box even on low the fans slow way down and sometimes stop. Is this amp really pulling that many amps or could there be a problem with my power supply.
I had one fan on the box and the other on my power supply. Thnx. Carlos aka Red |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 209
Registered: 9-2004
| | Posted on Saturday, February 05, 2005 - 8:56 pm: |
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there is an item i know of called a motor start switch. this is basically a switch with a built in capacitor. the reason its there is so that when you hit the switch, the motor has an instant burst of current to get the motor up to speed. logic would dictate that it takes a lot less energy to keep a motor spinning than it does to start a motor from a dead stop. im guessing that your fans need a CONSTANT current source. when you key the amp, you drain the caps down, and while they're recharging, the fans are slowing down. that is my guess anyway.
if it were my setup, i would run the fans off of a wall wart or a different power supply.
matt |
Tech291
Moderator
Username: Tech291
Post Number: 63
Registered: 11-2004
| | Posted on Saturday, February 05, 2005 - 11:26 pm: |
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most muffin style fans of that size only draw a few milliamps of power to run.it is possible the amp is feeding rf back into the fans solidstate speedcontrol having an effect on them.can you put an ammeter inline to check the power consumption on keydown? |
Red
New member
Username: Red
Post Number: 2
Registered: 1-2005
| | Posted on Sunday, February 06, 2005 - 8:04 am: |
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I had loaned my multimeter out and just got it back. I'm gonna check the amps and see. Thanks guys for responding. I think I might have a 12V wall adapter that would power at least one of the fans pretty easy. The Power supply seems to run hotter than the box, so one fan would probably be all I would need. It gets pretty hot down here on the Gulf coast and don't want anything to overheat. Thanks againg guys. Carlos |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 139
Registered: 11-2002
| | Posted on Sunday, February 06, 2005 - 2:01 pm: |
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In an electric motor that uses a capacitor, there is a thing called "start" winding and "run" winding. The capacitor does store a charge and when you turn the motor on, the switch that is in the back of the motor has it's contacts closed. This puts the capacitor in the circuit and uses that stored energy to "kick" the motor off. The switch has counter weights on it and working off of centrifical(?) force, the switch opens, closeing the capacitor out of circuit and putting the motor on the "run" windings, where the direct current from the input feeds the windings of the motor.
I use to work in an electric motor shop, just thought I'd throw that in.
What do you think would happen if you upped the capacitors in the power supply? The problem is that the power supplies constant amp rating isn't big enough for the constant demand the amp needs while you are talking. The surge rating of the power supply isn't big enough OR like Kid said the capacitors aren't charging fast enough to keep up with the amp. Most likely this is what's happening, since it's called a surge rating. Get a bigger supply. |
Tech291
Moderator
Username: Tech291
Post Number: 69
Registered: 11-2004
| | Posted on Sunday, February 06, 2005 - 6:12 pm: |
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tripplite ps40,32 amp constant 40amp surge
galaxy dx959 3.5 ampmax in am 100%mod
little red hooker amp 22 amp max at 13.8vdc
if the powersupply is not defective it has plenty of headroom for this setup
the 3.5INCH fans he is referring to do not have start caps,centrifical switches,only a small dc motor with frequency varible speed control.
tech291
CEF#291
kc8zpj
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Sg569
Member
Username: Sg569
Post Number: 97
Registered: 12-2004
| | Posted on Wednesday, February 23, 2005 - 11:40 am: |
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Ok, this one has me really scratching my head.
Anyone out there EVER have a amphenol pl259 just go bad? A month ot two ago I had a prob. w/ my coax, I was told that I had water in the coax and I should change coax( no prob. did that fixed prob.). I got to thinking that maybe I could use some of the old coax to make jumpers. I cut three feet off one end and put a multi-meter on it( hey better safe than sorry right?) It tested good. ( I can make jumpers!) I removed both pl-259s, and checked the rest of the coax, And I wsa shocked, the coax tested good!I started to test other parts of that assembly, and was very suprised to find out that one of the amphenol pl-259s was bad, it shows about 4.00 m ohms of resistance. After all that I didn't need to replace my coax after all. oh well, It was a good thing to replace the old coax(besides I needed trans. to fix two radios).
N-E-BODY EVER, EVER run into this kind of prob. before? Or is this a first?? It is for me, next time I have coax prob. I'm gonna check the connectors and the coax seperatly and see if I have to replace the coax or just the pl-259s.
Just wanted to know, that and let others know, too.
Thanks,
sg569 |
Tech808
Moderator
Username: Tech808
Post Number: 4975
Registered: 8-2002
| | Posted on Wednesday, February 23, 2005 - 12:08 pm: |
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Sg569.
Sorry but in roughly 100,000 or more that I have used over the years I have never seen or heard of anyone having a bad Amphenol or other PL 259 connector.
The center pin for the coax is 100% completely isolated form making any contact with the outer housing.
Unless the center pin has been extremly Over Heated until it can move and then it could only short if one of the shield wires came into contact with it.
Or unless someone did a sloppy job of soldering and the solder on the shield came into contact with the center pin.
100% of the problems that I have personally found with PL259 installations have been due to improper soldering techniques or overheating when soldering or those stupid useless Crimp on connectors.
And YES I have over heated many of them over the years and cut them off and put another one on. 
Volt/Ohm Meters save a lot of headaches.
Just my personal experience,
Lon
Tech808
CEF808
N9OSN |
Sg569
Member
Username: Sg569
Post Number: 98
Registered: 12-2004
| | Posted on Wednesday, February 23, 2005 - 1:37 pm: |
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Lon, I put pl-259s on the same way that tech291 does, Screw on the conn, after folding the shield back, then solder the center pin. The inside of the pl-259 is free of excess solder, the center pin is not loose( I cold solder w/ flux). The connector is showing that amount of resistance off the coax. I am thinking about popping the center pin and insulator out of the body and checking that out (just to satisfy my curiosity). BTW I have run this coax in THREE other mobiles at different time over the past 10 years, and this is the first prob. with it. YES, the coax was from rat shak I cut down 50 feet to hook up my mobile, and put the ends on myself. No, I dont use crimp on pl-259s I won't even buy coax w/ them crimped on( if someone GIVES me coax w/ crimped ends I cut them off before I use that coax).
Thanks,
Walter / Sg569/ CEF#479 |
Sg569
Member
Username: Sg569
Post Number: 99
Registered: 12-2004
| | Posted on Wednesday, February 23, 2005 - 2:31 pm: |
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ok, Lon;
I just took that pl-259 apart( the insulator and the center pin are now seperate from the body) and I checked the resistance from the center pin to the insul.and I have found what looks like a pencil mark inside the insulator near the center pin. if I touch my meter lead to that mark I show .986-2.190 m ohms. I have tried to shave that mark off and it look like it goes all the way through; I tried to hit that mark on the outside of the insulator and I get no reading. like I said this has got me scratching my head.
Thanks,
Walter/ Sg569 /CEF# 479 |
