Custom Amplifier

[GunSlinger338]

Are you on strong drugs,dearie me,big base station sound,wtf is that?:headbang:headbang

Echo makes people sound like an egotistical @sshole :thumbdown::thumbdown:,people don't envy it,they sit and laugh at the little boy playing with his noise toy.

Quality and echo are words rarely found in the same sentence.

OK .. no echo

How bout some reverb

 

[loosecannon]

i have to agree with gunslinger here, and i too believe that most people actually want reverb when they buy an echo box.

cb'ers didnt invent the idea of using a bit of reverb on your voice to make it sound "bigger". its been done in broadcasting for many years.

think about a guitar amp.
sure, it sounds pretty good dry, but when you add a little reverb, the sound opens up to somethig beautiful.


yes, many people have nothing good to say (you know who you are!), but they paid a lot of money for that radio and they are damn well gonna use it for something! LOL
so they key up and play with the echo knobs, thinking all the while that they somehow sound cool doing the exact same thing that they make fun of others for doing.

oh, for any of you out there that dont yet know how the cb game works; if someone insults you and "gets your goat", keying up a noise toy instead of coming back at them with a rebuttal means you automatically lose.
its a sure way to become someone's puppet. LOL

LC

 

[linearone]

I believe the only reason the amateur amps did it was to lower the voltage on the tubes,run them lighter in a carrier mode, and still achieve nearly the same power output. It was for efficiency basically. In CW or FM mode there is nothing wrong with class C but for any voice mode you need at the very least class B and then there is still some distortion but it is considered an even trade-off.Very few amps ever ran class B but here is a surprise for a lot of folks. A tube type AM broadcast transmitter runs the RF finals in class C and the modulator tubes in class B yet still attains a very low distortion figure due to lots of negative feedback in the audio section and by using plate modulation.

I know this. My 101 has class c finals. no one believes me when I tell them.

 

[GunSlinger338]

class C can be Clean ??? say it aint so !!!

 

[Captain Kilowatt]

I know this. My 101 has class c finals. no one believes me when I tell them.

I'm one of them.The tubes operate class B. If they are class C then someone has buggered the bias and there WILL be distortion. The finals in the FT-101 are not plate modulated and MUST operate in a linear mode in order to prevent distortion. This is a direct excerpt from the FT-101 service and alignment manual.

 

[Captain Kilowatt]

class C can be Clean ??? say it aint so !!!

Class C is perfectly fine for non-amplitude modulated modes where the carrier level remains constant.

 

[HiDef]

All the older plate mudulated AM/CW transmitters ran CW class C without key click problems. Thousands still in service.

 

[dudmuck]

All the older plate mudulated AM/CW transmitters ran CW class C without key click problems. Thousands still in service.

yes. those rigs were class C with only the final stage keyed for CW.
They had no key click problems because the key line had a simple shaping network.

However, if you key an exciter and then amplify it with a class C amp, then you can have key click problems with that.

 

[HiDef]

yes. those rigs were class C with only the final stage keyed for CW.
They had no key click problems because the key line had a simple shaping network.

However, if you key an exciter and then amplify it with a class C amp, then you can have key click problems with that.

I'm not too sure about that.

Key clicks are usually associated with fast off/on times like you said. Keying needs to be softened but not necessarily keyed at the final. It might be a function of self bias of the final that allows it to work. I have to ponder....

Collins 32V which is of course class a class C final. Paste from manual:

Keying is accomplished by means of grid block keying of the buffer stages. This keying is done on the buffer and first and second multiplier stages.

End paste.

That's just one of several old hammy transmitters that use a similar technique.

Maybe some of our hard core CW ops will chime in.

 

[W5LZ]

What you are taling about with key 'clicks' etc, is the rise and fall times of the keying circuits. There are various ways of 'shaping' those timing 'slopes' so that you can't hear the objectionable 'clicks'. That's done in all CW transmitters, not just amplifiers. How 'much' is done also varies for several reasons ranging from it just wasn't all that objectionable to start with, to a totally over done 'shaping' circuit that covered every imaginable situation. It's a very common thing for other 'on/off' or pulsed modes such as radar for just one example. Get ready to learn more than you ever wanted to know about 'RC' timing circuits .
The reason you don't see that much CW 'plate keying' is because the key was 'hot'. As in plate voltage present. You only made that mistake once, and remembered it forever. Also why there used to be 'covered' keys. You could still get the snot knocked out of you, but it was harder to do, sort of.
And no, I ain't no "hard core CW op". Once upon a time maybe, but that was a lot of years ago, so I don't qualify.
- 'Doc

 

[Captain Kilowatt]

What you are taling about with key 'clicks' etc, is the rise and fall times of the keying circuits. There are various ways of 'shaping' those timing 'slopes' so that you can't hear the objectionable 'clicks'. That's done in all CW transmitters, not just amplifiers. How 'much' is done also varies for several reasons ranging from it just wasn't all that objectionable to start with, to a totally over done 'shaping' circuit that covered every imaginable situation. It's a very common thing for other 'on/off' or pulsed modes such as radar for just one example. Get ready to learn more than you ever wanted to know about 'RC' timing circuits .
The reason you don't see that much CW 'plate keying' is because the key was 'hot'. As in plate voltage present. You only made that mistake once, and remembered it forever. Also why there used to be 'covered' keys. You could still get the snot knocked out of you, but it was harder to do, sort of.
And no, I ain't no "hard core CW op". Once upon a time maybe, but that was a lot of years ago, so I don't qualify.
- 'Doc

That happens with grid block keying too but not quite so bad. I still remember the time I reached across the desk and laid my forearm across the key contacts. That SOB had teeth in it and took a good bite out of me and yes I only ever did that once. I almost did it several times since then but the flashbacks prevented me from repeating it.

Key clicks are a product of the rise and fall times of the carrier and can occur regardless of the class of the amplifier. Usually a simple R/C or L/C circuit is installed on the key contacts to slow the rise/fall times down to prevent key clicks.

 

[bigred222]

ROFLMAO @ gunslinger!

that was too funny dude!
LC

I laughed too HAHAHA

 

[bigred222]

might as well go ahead and put nitro knobs with a mp3 player and a video display on it too .

like the connex 33tlm3

 

[Captain Kilowatt]

Honestly I can't pull a model out of the air right now but I do remember reading some articles,sale brochures etc, that did say about the bias changing when switching from CW to SSB modes.IIRC it was some of the older tube amps (Collins maybe?) One Yeasu radio actually switches bias to run pure class A if the operator chooses. It runs 200 watts in AB but only 75 watts in class A.

I finally found a model that has switchable bias and it's not nearly as old as I thought. I found it by accident while looking for something else.

Ameritron

 

[Beetle]

I finally found a model that has switchable bias and it's not nearly as old as I thought. I found it by accident while looking for something else.

Ameritron

I just turned a bit in my chair and looked at my AL-1200. Same switched bias scheme.