DX400 no transmit.. no preamp

[CarlAlberts0616]

Anytime you buy a used TS amp you should pull the cover and look at the chokes that Shockwave is talking about.
If they look discolored in any way, replace them.
If they get overheated and change value/short, it is a problem.
This is a issue that all of these amps have because of the way they are designed.
If in they had spent a few bucks more this could be avoided, but......
It is what it is.
73
Jeff

Ill check them out again, but i didn't see anything notable. This amp looks like it was never used or they were easy on it. Picked it and a superstar 200 for $100. Its not actually a TS but a copycat. Pretty close too. It works awesome though.

 

[AudioShockwav]

Does it say Outcom on the front?

73
Jeff

 

[2NC995]

Well.. This is dumb. Figured out the issue.. I think. So I noticed that the bench radio didnt have very strong receive. Normal people I talk to were pushing half what they normally do on the meter. Checked all my jumpers, no issue. Checked my SWR with my antenna hooked right in, it was sky high. Oops. It has been the same the last few years, I guess the wind storm we had did something to it last night.

So I took the box out to the truck and hooked it up with 2ga jumper cables and a good jumper just to test it out. BAM! Working great. Keys every time and its all working normal..

How dumb.. Thanks all.

Glad you got it working. I had an SWR issue the other day and ignored all the warning signs until the radio shut off a couple times.

Does he preamp work?

 

[Shockwave]

High VSWR places stress on the output components, not the keying circuit and diode. Unless the amplifier is oscillating...

 

[CarlAlberts0616]

Does it say Outcom on the front?

73
Jeff

Nope. It might be an old school TS, but doesnt say it anywhere. Says Bi lateral DX400.

Glad you got it working. I had an SWR issue the other day and ignored all the warning signs until the radio shut off a couple times.

Does he preamp work?

Yeah its working great.

High VSWR places stress on the output components, not the keying circuit and diode. Unless the amplifier is oscillating...

Maybe, not sure. But its working great in the mobile. Maybe im having issues with grounding.. Some weird stuff has been happening at my office with power supplys and what not.

 

[CarlAlberts0616]

I got this "Texas Star" and a Super Star 250 for a good deal. The 250 had a bad pill. Ended up throwing some Toshiba 2879s that were laying around in it. Works great now.

 

[2NC995]

Ended up throwing some Toshiba 2879s that were laying around in it. Works great now.

lucky lucky.

 

[AudioShockwav]

It is not a knock off.
The name of the models has changed a bit but the Bi Lateral 400 is a older Texas star model.
Yes on lucky.
Non red dot Toshiba 2879 transistors are hundreds of dollars now.
73
Jeff

 

[CarlAlberts0616]

It is not a knock off.
The name of the models has changed a bit but the Bi Lateral 400 is a older Texas star model.
Yes on lucky.
Non red dot Toshiba 2879 transistors are hundreds of dollars now.
73
Jeff

Thanks. Now i know.. Gues its real. Haha.

I haven't looked recently. We have a handfull of Toshiba pills sitting here.. Maybe ill off a couple for a few extra bucks.. Hm. Orrr stash them haha.

 

[AudioShockwav]

I hang on to them.
Stuff happens.

73
Jeff

 

[2NC995]

The other question would be...how did the 250 respond to a transistor swap?

Originally SD1446s?

 

[CarlAlberts0616]

The other question would be...how did the 250 respond to a transistor swap?

Originally SD1446s?

SRF3749 Motorolas originally. Honestly it works great. It took the new pills great. Had someone on it while i was out. It works good.

 

[9C1Driver]

I got this "Texas Star" and a Super Star 250 for a good deal. The 250 had a bad pill. Ended up throwing some Toshiba 2879s that were laying around in it. Works great now.

You can't just swap 2879's in there like that, several areas of the amplifier will need to be re-worked. Best bet is to replace the finals with the same finals if you can find them.

 

[CarlAlberts0616]

You can't just swap 2879's in there like that, several areas of the amplifier will need to be re-worked. Best bet is to replace the finals with the same finals if you can find them.

Yes, I am aware. I was setup for the 2879s by my uncle. An electrics/cb tech of many years. Its working great and for sale on ebay.

 

[CarlAlberts0616]

Texas Star is also for sale. Its doing 300 watts RMS, almost 500 PEP. Better than my DX500 with DEI pills.