Copper Talk » Ask The Tech » Amplifiers » Texas star 250 « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Bronzepony
Junior Member
Username: Bronzepony

Post Number: 49
Registered: 12-2005
Posted on Monday, April 17, 2006 - 10:38 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

A friend has a Texas star 250 that on channel 40 swings forward and on channel 1 backwards. SWR is 1.2 on 40 and 1.3 on 1. He has had this amp 15 years and it has never done this. He had changed to a wilson 1000 roof mount from a wilson 2000. we tried changing back to the wilson 2000 and it still did the same thing. He is running a General Lee in to it at 2 watts dead key on low and 13 watts on high never runs on high in to the amp!! swings 32 watts on high or low. He did tell me that he was running on high and did not know it the other day. Did he kill the trans. or something else?? If he killed the trans. can we put 2879 in for 2290's?? It still keys 110 watts.
Top of pagePrevious messageNext messageBottom of page Link to this message

Hotwire
Senior Member
Username: Hotwire

Post Number: 1193
Registered: 1-2005
Posted on Tuesday, April 18, 2006 - 1:58 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

How long has he been driving the amp with the General Lee? A 2 watt dead key is choice but 32 watts swing is to high for that little amp. I would not want to go past 20 watts swing. This is my opinion a dual final radio is not a good match for a 2 pill amp. Two 2879's mmmmaybe if you keep the swing down but definatley not 2 2290's. If the amp dead keys 110 watts thats to much. Try to get the deadkey down and see what happens with the backswing. Also turn the power mic down if you have one and see if back swing goes away. You may be getting a bad meter reading caused by reflect. Try these things and other ideas like different antenna and coax and jumpers. good luck
Top of pagePrevious messageNext messageBottom of page Link to this message

Audiophile73
Member
Username: Audiophile73

Post Number: 91
Registered: 5-2004
Posted on Tuesday, April 18, 2006 - 3:35 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I've never heard of that happening. I'm sure it's not the antenna, but if you wanted to rule that out you could try running it on a dummy load. Open it up use a DVOM (digital volt ohm meter) to check resistors and stuff.
Top of pagePrevious messageNext messageBottom of page Link to this message

Patzerozero
Senior Member
Username: Patzerozero

Post Number: 2729
Registered: 7-2004


Posted on Friday, April 21, 2006 - 5:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

that dx250 should be dead keying around 40 watts & swinging to 160 or so. downwards swing is showing too much input. no way will 2 watts input allow it to key 110. if it's showing output still, the transistors have not been 'killed'....yet
Top of pagePrevious messageNext messageBottom of page Link to this message

Bronzepony
Member
Username: Bronzepony

Post Number: 52
Registered: 12-2005
Posted on Saturday, April 22, 2006 - 12:18 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

This was on a Dosy 1000 meter???? Checked it agian may try a diff. meter!! Found his ground was not good!!! tried to tell him that ground is as important as power!!
Top of pagePrevious messageNext messageBottom of page Link to this message

Vanillagorilla
Advanced Member
Username: Vanillagorilla

Post Number: 539
Registered: 4-2005


Posted on Saturday, April 22, 2006 - 12:37 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

...to further expand on Pats post...if you were to check that on an RMS meter you would see neg swing likely on all channels. No WAY should that 2pill be keying that much. I think he has to recheck his input power. Sounds like he putting more like 6-8w DK into that kicker.
This whole scenario (sp?) sounds like when I forgot to turn down the DK on my Pluto before hitting the Pal225. I forgot it right through a whole skip shoot afternoon! When all was said and done I had smoked one MRF455...DK remanined pretty much the same as it did before (on low) but had nearly zero to very little swing..replaced both with SRF3775's which were a SLIGHT upgrade powerwise and still work great with either the Galaxy Pluto swinging 20+ from 3w OR the Magnum Delta swinging 40 from 4w input. I see around 200 PEP (130ishRMS)from a 40w DK on low....which is where it sounded best.

Good luck
Hank CEF559
Top of pagePrevious messageNext messageBottom of page Link to this message

Bronzepony
Member
Username: Bronzepony

Post Number: 53
Registered: 12-2005
Posted on Saturday, April 22, 2006 - 9:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Think I figured it out!! The way that radio is mod. no limiter with a amp it is keying 7-8 watts turn the mic gain to 3 o-clock and it will Key 2. Have yet to test this on this truck put I have one here that I am playing with! I know never pull the Limiter just wanted to set up like it was to see!!

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: