The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

kc8mob

shuttttttttttttt up and leave ramblin man alone i,ll bet him and rick are much smarter than you and they dont try to get rich doing it they help for free and they know what they,re talking about

Yea, most people are full of shit. "Modulator" LOL. Most of these "mod" guys couldn't even tell you ...

kc8mob

Well, I've only owned a few galaxy's but I never had all the problems you mention. Then again, I rebuild every radio I buy.

Lots of simple shit can go wrong in mass produced shit.

First thing first is to bring them to life.

kc8mob

Can someone please explain the "modification" of converting you stock Ranger (Galaxy, Mirage, etc.) roger beep to a roger fart.

How STUPID is that, it's bad enough that people don't know when and where to use a Roger-Beep, and then someone wants to make it more annoying. Give us all a break ...

kc8mob

http://home.att.net/~wizardoz/cbmw/antenna_fabri.html

kc8mob

I'll find you a link, should be even better.

kc8mob

Well as usual making simple diagrams doesn't work on forums like this.

kc8mob

Make a di-pole!

Coax, and two pieces of wire 103 inches long, minus 3% to be axact.

102" 102"
-----------------I---------------
.................... ^
Coax feed point

One wire goes to the center conductor of the coax, the other wire connect to the shielding of the coax.

Radio 101 :!:

kc8mob

What are all the /numbers. like hobothe bobo/898 for example.

What do the 3 numbers mean?

Adam

kc8mob

Well you should really just use a 100K resistor instead of a diode.

Furterh more, are you finals alive with 13.8 or they still run by the 2sb754

kc8mob

Yes,

But your finals should be running off of 13.8 volts right out of the filter choke.

kc8mob

Well all you guys need to keep in mind that efficiency of operation translates to output power.

All of that jazz that matches final up with driver has to do with this.

Impedance matching as well, which translates to efficiency.

Basically, efficiency is the key.

kc8mob

RFI filtering.

kc8mob

A cobra 148 already has a 2sc1969 final in it. So changing it out was a waist of time.

Other then that, those finals will functionally replace discontinued transistors. Doesn't mean they are superior and will yield better results, just that they will mount, operate and survive mobil RF applications ...

kc8mob

What is the model of the radio exactly. Like a tx something or other.

kc8mob

Well, here's the scoop. You've all been bad, so all you get for xmas is snowman poop.

No just kiddin'

Change C90 to a 3.3uf or 4.7uf. RemoveC119, and run a 1000uf cap from positive side of C119's position to the base of TR34, with the positive side of the 1000uf cap going to the base of TR34 ...

kc8mob

Just google your radio.

kc8mob

I'm trying to help a friend who is in AZ to jack up his yard sale score.
A cobra 140 GTL, I gather that this rig is the same as a 142.

So, sense it's not here, I can't just figure it out by looking at it.

What do you do, specifically to drop the carrier on AM and get forward power on AM.

The goal ...

kc8mob

The same pricipal behind the super mod kit for all other radio would apply here.

Get at the driver. If it uses some form of regulator, then you have to take the eportish type of approach.

Is this thing SSB?

kc8mob

Have you figured out if the lights are getting voltage, or is it the bulbs. Or LEDs.

Most likely the 7808 regulator is shot

kc8mob

Yup. My 2970 is a little much for my AL-811H Ameritron amp.

But it's tube type, so you can get away with drving it a little hard. Also, I can get tubes pretty cheap and they just pop right in.

Honestly though. A 300 watt linear isn;t going to do any more for you then the power oputput of that ...

kc8mob

Marine antennas use the ocean as a ground plane.

kc8mob

You need a big ass amplifier with that much output power.

Look for something around the lines of 700 to 1KW

kc8mob

You're going to need something that can take a fair ammount of input.

How much RMS power is your rig outputing. That's the real question. Once you atart talking linears, you have real power and don't have to fool yourself with the whole PEP wattage measurment.

So get an amp with about 4 2sc2879s ...

kc8mob

Did all of this happen after you installed the roger beep

kc8mob

What and where did you get your power cource for the roger beep.

kc8mob

I'll plop 'em in the mail tomorrow.

kc8mob

Send me your address and I'll mail you some. You have to use the real thing, because they are thermaly conductive.

They electrically isolate, and thermally couple. Without the right shit, your final will melt down.

kc8mob

You have to make sure your screw that holds the final to the heatsink is insulated too. It has a little bushing that goes on the shaft and seats on the head of the screw.

kc8mob

You can order them when you buy your new finals.

kc8mob

Buy your self a linear instead. cobra 29 and a 300-350 watt linear will walk all over a connex.

Well, besides the power, it would be better, unless your trying to get into ssb and what not.

2950 would be better then a connex.

kc8mob

Sometimes I get tired of typing.

kc8mob

LMAO.

Those are insulators. And yes you need to use them. The back of the transistor is metal, and it's common with the center leg of the transistor.

Meaning it has to be insulated electrically from the chasis. If you did not use these when you changed the finals in and out, the finals no longer ...

kc8mob

Sounds like sombody has a CB on 13 around you.

You know, you hook one up to a car bat. and dead key the rig, you can kill somebodys recieve on what evber channel.

Good prank actually

kc8mob

Is your power supply producing voltage. Not on short circuit protect. Or bown fuse.

Check the DC resistance accros the hot and ground pin with the switch turned on.

kc8mob

You have ground loop problems. You're getting your power ground through your coax. Means you antenna is grounded well, which is good.

kc8mob

IS your rig on PA?

If not, it sounds like you lifted a trace somewhere. The fact that the old final doesn't work either is a good sign.

Are you sure your cap and resistor mod is still intact?

kc8mob

Ground problem in relation to channels.

For the power output. It could be allot fo things.

kc8mob

The stock driver in 29s should be the 2sc1957. no matter what.

The 2030 is only out there for the replacement of the 1969. the 2030 is no better, just will be availible for the next good while.

As for RMS. That really is the important figure. PEP just makes you smile.

Think of it as average ...

kc8mob

Now you;re thinking.

kc8mob

Have to factor in the velocity factor of the coax too when you're doing your figureing.

kc8mob

Using both is easy, Either use a relay to switch between the two or. Or co-phase them. You'd have to use a delay cable feedlin though to get it right. Like an extra 1/2 wave length of the opertaing freq. in coax.

kc8mob

get a 7808 and chasis mount it by the power plug. Simpel IC voltage regulator

kc8mob

Boy this feller named Rick is a smart one. I thought I was the only one.

kc8mob

Or maybe it's the 2sc1057 that's stock in those radios. I know it didn't use to be what you said.

Anyways, if you're going with the 2sc1969. You don't need to replace the driver.

kc8mob

Wow they changed it then.

kc8mob

Uhhh. Your radio already has a 2sc1957 driver in it.

kc8mob

Just reverse engineer it. Draw your own digram. You know which way it's suppoed to be. the little notch in the plug. Then label where the wires go on the board. So just make the wires attach to the right spot with out the board.

Too easy

kc8mob

Well you can pull some ceramic caps and switch some around when you do the 1969. But it's a drop in mod. Unless you're getting 40 watts PEP easily out of your rig with the ERF 2030 it's allot of work.

But, there is no more right way with either so it's up to the guy who's willing to experiment with ...

kc8mob

MCM electronics. Eaby. Copper electronics, just google 2sc1969. This way you'll find it for less. CB dealers are going to rip you off.

kc8mob

Here is a reputable source for linears: http://www.amateurlinearamplifiers.com/cgi-bin/cart.cgi

and just get a 2SC1969 final for your 29. they're still availible so use it. Much easeir. The 2030 is a replacement for the 1969 since it's been discontinued. But you can still get them

The 2030 ...

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Re: Roger Fart

Cobra 140 GTL/142GTL Mods. AM super mod???