| Author |
Message |
    
Shadow357
New member
Username: Shadow357
Post Number: 1
Registered: 5-2005
| | Posted on Saturday, May 14, 2005 - 11:57 am: | 
|
Recently I purchased an 1150v from a "dealer" and after several attempts to contact them I am basically on my own
Heres the problem upon removing a twister xl900 from the truck (class 8)and installing the new amp I went to checking the output of it and found beutiful swing on the bottom end, once I got past the 12 oclock mark and started doing some bigger numbers (600 watts) a cloud of smoke came out of the box.
Ok heres what I found wrong on my end, my swr were at 2.1 (I know I shoud have checked it) other than
that everything looks to be fine, I have ohmed out the coax,jumper and got the swr down to an accapteable 1.2 on 27.2250mhz
Now the source of the smoke at the rear of the box there are 3ea. 100ohm 3 watt resistors, 2 of the three have toasted. After replacing them once again poof at the higher numbers.
Are the chances of burning out the 2879's fair to good ? being from what I understand that if one of them do toast they will feed back to the resistors?
Also and finally I noticed that this box is built with a 2879 driving 6 2879, I havent seen this before and wonder if it was designed this way or maybe a 2290 should be driving instead?
I have pics of the unit , but cant upload them here due to size limitations, I can send them to whoever may be able to help |
Couchpotatoe
New member
Username: Couchpotatoe
Post Number: 6
Registered: 6-2005
| | Posted on Monday, June 13, 2005 - 9:27 pm: |
|
IF IT IS THE RESISTOR BETWEEN THE OUTPUT COMBINER THEN THE TRANSISTOR S ARE OUT OF BALANCE AND THEY ARE OR SOME TOAST |
Heavyweight
Junior Member
Username: Heavyweight
Post Number: 13
Registered: 11-2004
| | Posted on Thursday, June 16, 2005 - 8:07 pm: |
|
1 2879 driving 6 2879's????Maybe i havent been around enough but i never heard on this.Whatever works i guess. |
Chipotle
Junior Member
Username: Chipotle
Post Number: 25
Registered: 3-2005
| | Posted on Sunday, June 26, 2005 - 10:31 pm: |
|
resistors burn in the combiner due to a imbalance only.odds are 1 2879
transistor got destroyed in the swr dilemma you once had continue replacing
resistors will not solve anything box sounds like it was set up for a high
drive radio like a export and if so this is ok.test the transistors or send
the box for repair.
|
Nightmarenyc
New member
Username: Nightmarenyc
Post Number: 9
Registered: 1-2005
| | Posted on Saturday, October 01, 2005 - 10:24 am: |
|
If 2 out of 3 of these resistors are burnt, you have @ least 1 pill blown in each respective bank. You can change those 3 watters(?) all you want, but they are goin to keep blowing. Look @ the base of each pill and you should see a small 10 ohm resistor (brown, black, black). If any of these are burnt/discolered, that pill is gone and has to be replaced. |
