Audio monster

[15minigrass]

Theres a deal!!!

Or...you could buy my S6 nitro, save about $100 and have a big audio radio that does 60 watts at 14v in one fell swoop.
preacherman

 

[cbradiomagazine.com]

I wrote an article about some of the favorite audio monster radios....

Audio Monsters

 

[74IN]

Smalltiredart and Librium, I agree.
I have a 68 and love it.

Did this, give it a try.

 

[AudioShockwav]

The Yaesu FT-101 and FT-102 are two very popular transceivers with the CB radio crowd because of their high quality and multiple functions. But multiple people have made reference to their AM audio loudness and quality.

Before anyone starts yelling at me I'll point out that NO these are not CB radios. These are ham radio transceivers and have to be modified to be used on 11 meters.

The FT-101B and some early 101E`s had 11 meters right on the band switch, and with out a doubt were awesome on AM. The single biggest mistake made with these radios`s was to try to run the dead key (carrier control) too high. While these radio could easily exceed 100 watts on SSB, for best results on AM they need to be run at 20/25 watt carrier level.
At that setting, you will find that you do not need to exceed about 50% on the Mic gain...hard to beat plate modulated audio
A lot of the early cb radios used high level am were Mic audio was feed to the Audio IC, then a transformer that added the audio voltage directly to the DC supply voltage going to the driver and final. The result of this is collecter voltage that varies at an audio rate. A good example is the TRC 433.
Soon after they stopped using transformers, and used the audio Ic to drive a couple of transistor`s in a current amp circuit( cobra/uniden) or a "darlington IC" (cybernet) set up.
Both ways can produce very robust audio levels in AM mode, even more so when compared to low level Am that is used in most current ham rigs, or even some radios like the president jackson or the old CPI radios, like the CP 2000.
Not that Low level don`t work, it is just much easier to get more "punch" modulating the collecter voltage.
Now having said all of this, it is still easy to go overboard, and wind up with raspy/overmodulated audio with any of the methods used to modulate a carrier if AMC limiters are ripped out and the radio adjusted wrong.
A lot of the guys you hear running the old 101`s or a old Johnson on AM, have nice, smooth, bold audio. And it is because they take pride in a good sounding radio.
73
Jeff

 

[King Mudduck]

Both of my FT101-EE's rock on AM!

 

[bigred222]

THERE IT IS THE NEW 939
Thanks minigrass for posting the pic i couldnt find it anywhere. Looks like a sweet rig.

 

[Number15]

Thanks for all the replys, yea i run right now a Galaxy 99v into my amps. and sometimes some 29s that i build and locals say that the 99v is loud. So i will run it for local talking. heard good reports about magnum s9s ? so i might be looking for one Thank again #15 in Cali.

 

[dudmuck]

While these radio could easily exceed 100 watts on SSB, for best results on AM they need to be run at 20/25 watt carrier level.

yea the rule for 100% AM modulation is that at 100%, the PEP is 4x the carrier power. So 100% modulation of a 25 watt carrier would be 100 watts PEP, and the RMS power at 100% modulation would be 1.5x the carrier (37.5 watts RMS).

Too bad the TRC-433 has no documentation on cbtricks.

As far as low-side modulation, one thing that comes to mind is the difference between 2-quadrant and 4-quadrant modulators, as described here: http://www.williamson-labs.com/480_am.htm
I would suppose it would be easier to get audio punch from a 4-quadrant vs. the two-quadrant modulator. The 4-quadrant modulator becomes ssb-ish with overmodulation instead of cutting off the carrier and splattering.

 

[thedirtmover]

A cobra 29 or 25 or uniden counterpart that is well built with all the right mods will smoke any export radio when it comes to blaring loud audio, heard it done many times. Of course they will not do 40 to 50 watts ( more like 20 to 30 ) like just about any duel final export will but then again big power is really not everything like a lot of people think.

I disagree, they are very capable of 40 to 50 watts.

 

[cbradiomagazine.com]

Cobra 25, 29 are only able to do 40-50 watts with extensive modifications....totally not worth the $$$.

I have a heavily modded Cobra 21 LTD I did up that will do 30 watts and is super loud, but I admit that the radio is a complete bleedbox.

And there are very few real Cobra 29's doing 40-50 watts. To anyone who has one they think is doing 40 watts...they are welcome to put it on my meter and find out the "real" watts

I agree completely with what was said about the old johnsons and FT101's amazing audio when run right..and that goes for the old Trams as well.

My Old johnson base I just recently sold deadkeyed 2 watts swinging to 10 - but I could talk barefoot and it would get out! Most amazing audio of any radio I've ever heard on the air - the old johnson power desk mike used a hot pin from the radio for the power and it provided super clean loud studio type audio.

When I ran it with a small amp at 100 watts I could talk on the bowl with all of the big boys. People always asked me what kind of radio I was running

 

[Number15]

I know a few people here on the west coast that run johnsons, my brother is one and he talks bearfoot from WA, to Ca no problem. I have a FL 101 that talks great too.

 

[BOOTY MONSTER]

skip is our friend

 

[Number15]

Yea still waiting for SKIP lol #15 around the shakey

 

[DTB Radio]

A cobra 29 or 25 or uniden counterpart that is well built with all the right mods will smoke any export radio when it comes to blaring loud audio, heard it done many times. Of course they will not do 40 to 50 watts ( more like 20 to 30 ) like just about any duel final export will but then again big power is really not everything like a lot of people think.

I disagree, they are very capable of 40 to 50 watts.

I have to agree. With a supply voltage of 14.3 volts during testing, I've seen well over 60 watts out of a Cobra 29. Now that was on max peaks, including the spike caused by inductive kickback from the transformer when the AMC isn't kicking in, and using an o-scope to calculate that reading. As fas as actual usable power, I'd have to say that they are definitely capable of anywhere from 40 to 50 PEP.