Search results

I use a 148gtl with a 6db pad. Works well. 52v DC supply. Just remember, the BLF188XR does not like to be overdriven. 2 keys is all I got the first time. Then pop. Proper drive level and understanding it is important. $200 lesson for me. Don't make the same mistake.

I've had good luck with blf188xr from one I built so far. Still needs filtering. With 3.5w drive I'm getting around 1100w pep. I used a broadband transformer instead of transmission line transformer with good results. Built from scratch. Tracking bias is important.

Glad it was easy fix.

What I mean by AC and DC, one of those wires carries your rf signal should have a bypass cap to let rf thru but block DC. On same line/ feed has DC to feed bias circuit. That is why there are chokes. To let DC voltage thru but block rf voltage. It's an old TS trick.

Could be the pin arrangement on relays is different. Yours has class B biasing so bit more complicated. They use similar design in TexasStar amps. You have AC and DC going thru the line.

Mrf454's like 12-15vdc. Not sure what you mean by variac on top of transistors?

Besides what Nomad stated, you might want to try a low pass filter between radio and amp. It's possible that radio is a generating a lot of harmonics and the amp is just amplifying it. What radio are you using to excite this amp?

How much carrier / DK are you putting out. I'm not familiar with that amp. But if the amp only hums when keyed wondering if pulling too much. Or maybe something off on biasing. I'll have to look up amp and see what tubes are in it.

It's not just the amp. Most XForce I have seen are decent. Usually it has something to do with driving the snot out of it. Volting and driving the snot out of and or a really bad match on antenna system.

It's true regulated biasing. I've give em that. But can't get past plastic case.

I don't like the plastic case. Can't be good for rf shielding.

Did anyone ask what meter or meters were used. Not a Fluke, but the power meter. I have a 1x2 here that does crazy watts as well, but after it was tuned properly. It fell inline with the math. Lol. It was an old Buckeye Bully. Showed 350w average and over 600 pep on a Bird meter with a true...

LOL, good luck getting 572B's. They are scarce nowadays. It's a long waiting list.

What radio are you using and what does it put out on SB? That's the first thing that should be asked when getting an amplifier.

Your doing good so far. Jumpers, coax, ground and match are the first things to check. Next is a few different radios. If they are butchered or an improperly tuned export, good luck with that. Next is the amp itself. Lol, that's when it's time to stock up on 465's and something like 4610 or 4615's.

I'm not gonna say it is the issue with this amp. But I have come across a lot of amps that weren't tuned right. Not just changing the value on the input and output. But the actual value across the transformers as well might have to be changed. LC can go into more detail if need be. But I'm...

Base amp or mobile amp? What is configuration? 1x2, 2x8? What transistors, DEI or Toshiba or PP100 or whatever?

Replace the fan. It's shot.

I have only used the pp100 transistors once and it was to repill an 8 pill messenger. That is the only dealing I have had with them. So I apologize for not being able to be more specific. I'm thinking that 8 transistor amp only needed 15-17w carrier for the 8 to DK like 250-300w. It's been...

The TNT 2 pill I think uses the PP100 pills. If that is what is in it, they only recommend 25w DK out of each pill. Meaning that 2 pill should only DK 50w. Now I know these transistors need a bit more drive. But if a 5w carrier produces more than a 50w carrier out of amp, then yes it is too...