More mod

[Wayne clevenger]

Question How to hook a 250 killer bee and 100 watt modulator in line with cb,any help would be appreciated.

 

[Tokin]

One or the other but not both unless you dont like the 2 pill much.

 

[543_Dallas]

Bad idea to drive the 250 with 100 watts. It will smoke the unobtainable transistors in the 250.

Lower the deadkey from the radio enough to get 40 watts deadkey from the 250 and let it swing. No more than 15 to 20 watts pep into the 250. JMO

 

[9C1Driver]

2SC2290 TOSHIBA Transistors, Matched Pair (2) (Early Version)
$210.95


2SC2290 Matched Pair - 2 Transistors, Silicon NPN Epitaxial, MFR: Toshiba No longer available for Export, (NOS)

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Not sure who told you to run a modulator into a Texas Star 250 but please have a fire extinguisher ready if you decide to make such a poor choice. As you can see above Toshiba finals are very expensive these days, if you can even find them.

I have two Texas Star 250 HDV amplifiers that I run mostly SSB with. I can get 210-240 watts PEP from both with just 8-10 watts PEP input on SSB. The amplifier runs much cooler this way as well.

If you run AM use JUST a radio for a driver. Turn the dead key on the radio down to whatever it takes for the amp set on HI to dead key 40-60 watts. As stated 15-20 watts peak drive on AM should be plenty.

 

[groundwire]

Question How to hook a 250 killer bee and 100 watt modulator in line with cb,any help would be appreciated.

If you need help on how to put an amp in line then dont, you're not ready.

 

[144inBama]

The modulator was/is intended for the older DX500s and larger. The new 500s with the DEIs can't handle it as well, unless you're running low voltage thus reducing the output of both. That 250 is meant for radio drive only.

 

[AudioShockwav]

In all honestly I would not drive a mod or mod v into any ts 500 anymore.
The transistors are just too costly to replace now and the increase in power is not worth the risk, even on the old ones.
It if was a class c comp box, yes you might get away with it, but the Toshiba's are just too much money now.
73
Jeff

 

[Tokin]

Question How to hook a 250 killer bee and 100 watt modulator in line with cb,any help would be appreciated.

And welcome to the forum. Great peeps here who really enjoy the hobby of radio. Everyone from noobs to extra class amateur operators here. Its a really great group of people.
Id like a mod v for my 8 pill 2879C amp im waiting for. Hit me up if you decide to let it go.

 

[Slowmover]

As a question: If 100W won’t do the job, where else can efficiency be improved?

Shoot, I keep removing & replacing the gear in the Peterbilt. Tonight, 8W will crank 90W+. At about 1.2-W Reflected.

A better SWR than this morning. LOWEST YET!!

Back it down under 8W (Galaxy 99v2) and tomorrow ask for reports to back it down some more (into a KL203P).

It’s now taking less G99 power to hit 75W.

I’ll bet I can find a base station or other operator can give me some feedback from a fair distance. Park awhile. Run the range of adjustments (Mic Gain + three different microphones, not just power).

There’s a limit to how efficient is my system.

One where Mo Powah! ain’t a help any more.

Time to work on Intelligibility.

(Welcome!!!)
.

 

[Slowmover]

Just had Super Fly come booming in from a measured (24) air miles south on IH95 in Virginia (he’s in Fredericksburg. Says his mobile connected to an antenna on a tower at 175’. I believe it).

Said I was hitting him clearly at S-3.

(It’s an hour or so past sunset, and I’m parked in a rural area surrounded by other big trucks. SF is “behind” me. Weakest direction for me).

Given the crappy antenna mounts on a fleet-spec company Peterbilt, that’s been a long time coming.

Pair of cophase 5’ Wilson 2000’s seven-feet apart and topping out under 14’.

.

 

[Handy Andy]

Question How to hook a 250 killer bee and 100 watt modulator in line with cb,any help would be appreciated.

I'll leave this Illustrated
Instruction Manual here...
​

Because you may need it....

 

[TM86]

Question How to hook a 250 killer bee and 100 watt modulator in line with cb,any help would be appreciated.

I hope you mean to switch the amps out and not run radio->100W->250W.

If you do, that signal will be a bit of a mess for the milliseconds you're on the air before you fry the 250, the 100, and possibly the radio.

If that is your intention, please take video and post it here. Make sure it's well lit so as not to miss the magic smoke escaping from the boxes.

 

[BJ radionut]

He posted the question, then has not logged in since!
Anybody smell smoke?

 

[Tokin]

He posted the question, then has not logged in since!
Anybody smell smoke?

Of the 10 ohm variety?