A question.... again.... to up my education......

[guitar_199]

It may seem surprising....me asking this at THIS point in the game....but I've heard it for so long......and don't have my head around what it is......

WHAT is a "swing kit"?

[edited to clarify]
What does it DO in there.... that a "well maintained and aligned" radio does not already do???

Cutting it even "more to the point"......

What does it do that is worth paying for?

 

[w9cll]

WHAT is a "swing kit"?

it over inflats your ego by making you think your radio is out putting more than it actually is.. I

Really what is does is allows you to deadkey low watts and then shows more watts when you talk...ahh just ssb but on am. Generally it is useless and not worth wasting money on.

 

[Handy Andy]

Hmmm...Good question...

A good way to understand this, is to look at the "Datasheets" the Final and Driver are "classified" Cataloged or otherwise specified...

​

The "Device Under Test" Circuit only produces so much data, the rest is how you utilize the transistor, OR MOSFET, to operate in a non-linear, but linearly - power curve.

Some Datasheets provide a Bias design for their specific part, but it is RATED for that particular Bias as a factor of Class Of Operation - Conduction Angle or duration the part is on, during the Single-Sine Wave cycle (if you think of it that way - it helps to know the time on to time off as a percentage or 70% Duty cycle - or 70% conduction angle) - as an example.​

​

This is what makes the "Swing" part - the rest is what is "Tailored" by you or your tech, to produce a given envelope of power around this effect.

​

Now, I said "effect" because that is what you're doing, is utilizing a part to generate a wide power curve - in a narrow range of power level "change" on it's input.

The Transistor has a Characteristic Impedance, a reaction - to the amount of input power being applied to reflect - mirror, amplify - the power that is produced on the output. A series or sum of Vectors, both in phase of Voltage and Current, as well as it's "power level" at that moment in time in the Input power - then can be processed by the PN junctions of the Transistor - to produce an output mirroring the vectors with characteristic changes caused by the processing the transistor places itself under... Remember that RF or any form of AC signal; be it RF or even audio - works or vectors with - Inductive and Capacitive effects that are part of the power curve. So if you need to reproduce any RF wave - you need to allow for and account for the Transistors willingness to cooperate or alter the waveform - either faithfully or destructively.

Same can be applied to Linear Diffusion (or device) MOSFET designs - that are made to offer a region, or power level - that isn't fully on or off, but works like a transistor - but offers a different input impedance. Being much higher, can't process current - but will provide large amounts of current swings (draw amperage) as a relfection or mirroring of the inputs..

To overcome this limitation - a voltage component is used - in Bipolar design - they require current - but in both parts, some voltage is necessary to overcome the inherited characteristics' like "voltage drop" that will affect how the power curve develops - a factor of Class Of Operation. - Class A being the most faithful reproduction at a cost of conduction and power dissipation on down to lower levels of conduction - Being Class B and following the letters of the Alphabet. Class B the next most "faithful" while latter Class types are placed below that in levels of conduction the parts produce.

So to put this in a light of what we do with CB radio, we try to force the carrier from being a "Steady state" constant, into a variable power curve we tailor to suit the needs of the customer;

• be it audio drive, or power level - you can change the operation of Class by changing parts in the Amplifier stage to achieve these various effects.

 

[guitar_199]

Handy Andy,

Thank you very much for this, I am going to copy/paste it out to a doc that I can study when I am not working.

This is leading to expose a weakness in my understanding......

PRACTICAL USE of various "classes of bias" on transistor devices.

I am currently reading the section in Lou Franklin's book on transmit and it talks about the use of Class A in certain parts (amplification primarily) and Class C in others (mixing and modulation, which is actually a kind of mixing).... I am KIND OF getting it... but have miles to go!!!!!!!

Thanks again!!!!!
Bob

Hmmm...Good question...

 

[Tokin]

it over inflats your ego by making you think your radio is out putting more than it actually is.

Really what is does is allows you to deadkey low watts and then shows more watts when you talk...ahh just ssb but on am. Generally it is useless and not worth wasting money on.

For those running barefoot they are useless. Those using a amp may prefer to utilize one.
You generally see variable controls on base stations but not so much on mobiles. I think because mobiles get bounced around a bit and easily knocked out of adjustment. Id expect to see this mod used on a mobile being ran as a base station as i do atm.
My 29 will go from 0 watts dk to 4.5 watts.
I dk 3/4 watt and swing to 35 watts pep with the mosfet mod.
3/4 watt into my Palomar 300A on the high side gives me a 100 watt carrier swinging to 250 watts bird or about 600 pep on my 43P.

 

[1iwilly]

am radio have a swing kit and the ssb radios have what is call NPC mod

 

[w9cll]

am radio

Real AM doesnt swing.

 

[Handy Andy]

Now, look carefully...

Swing
[swiNG]
VERB
swing (verb) · swings (third person present) · swung (past tense) · swung (past participle) · swinging (present participle)

1. move or cause to move back and forth or from side to side while suspended or on an axis.
   "her long black skirt swung about her legs" · "a priest began swinging a censer"
   synonyms:
   sway · oscillate · move back and forth · move to and fro · wave · wag · dangle · rock · flutter · flap · vibrate · quiver · brandish · flourish · wield · raise · shake · twirl
   • informal
     be executed by hanging.
     "now he was going to swing for it"
   • turn (a ship or aircraft) to all compass points in succession, in order to test compass error.
2. move by grasping a support from below and leaping.
   "we swung across like two trapeze artists" · "the Irishman swung himself into the saddle"
   • move quickly around to the opposite direction.
     "Ronni had swung around to face him"
   • move with a rhythmic swaying gait.
     "the riflemen swung along smartly"
     synonyms:
     stride · march · sweep · stroll · sashay
3. move or cause to move in a smooth, curving line.
   "the cab swung into the parking lot" · "he swung her bag up onto the rack"
   • bring down (something held) with a curving movement, typically in order to hit an object.
     "I swung the club and missed the ball"
   • (swing at)
     attempt to hit or punch, typically with a wide curving movement of the arm.
     "he swung at me with the tire iron"
   • throw (a punch) with a swinging movement.
     "she swung a punch at him"
4. shift or cause to shift from one opinion, mood, or state of affairs to another.
   "opinion swung in the Chancellor's favor" · "the failure to seek a peace could swing sentiment the other way"
   synonyms:
   change · fluctuate · oscillate · waver · alternate · see-saw · yo-yo · vary · shift · alter · undulate · ebb and flow · rise and fall · go up and down · go back and forth
   • have a decisive influence on (something, especially a vote or election).
     "an attempt to swing the vote in their favor"
   • informal
     succeed in bringing about.
     "with us backing you we might be able to swing something"
     synonyms:
     accomplish · achieve · obtain · acquire · get · secure · net · win · earn · attain · bag · capture · grab · hook · maneuver · sort out · wangle · land · fix (up) · work · get hold of · nab · collar · pull down · knock off
5. play music with an easy flowing but vigorous rhythm.
   "the band swung on"
   • (of music) be played with an easy flowing but vigorous rhythm.
6. informal
   (of an event, place, or way of life) be lively, exciting, or fashionable.
7. informal
   engage in group sex or swap sexual partners within a group, especially on a habitual basis.

NOUN
swing (noun) · swings (plural noun)

1. a seat suspended by ropes or chains, on which someone may sit and swing back and forth.
   • a spell of swinging on a seat suspended by ropes or chains.
2. an act of swinging.
   "with the swing of her arm, the knife flashed through the air"
   synonyms:
   swaying · oscillation · undulation · wagging · toing and froing · wobble · libration
   • the manner in which a golf club or a bat is swung.
     "improve your golf swing"
   • the motion of swinging.
     "this short cut gave her hair new movement and swing"
     synonyms:
     sweep · wave · roll · shake · movement · oscillation · undulation
3. a discernible change in opinion.
   "the South's swing to the right"
   synonyms:
   change · move · turnaround · turnabout · reversal · about turn · about face · volte face · change of heart · change of loyalties · U-turn · sea change · swerve · backtracking · tergiversation · trend · tendency · drift · movement · current · course · fluctuation · shift · switch · variation · oscillation
   antonyms:
   stability
4. a style of jazz or dance music with an easy flowing but vigorous rhythm.
   synonyms:
   rhythm · beat · pulse · cadence · pace · rhythmical flow/pattern · measure · meter · tempo · lilt · groove
   • the rhythmic feeling or drive of swing music.
5. NORTH AMERICAN
   a swift tour involving a number of stops, especially one undertaken as part of a political campaign.
6. (in musical theater) an understudy, typically one who covers multiple roles in the chorus of a particular production.

ORIGIN
Old English swingan ‘to beat, whip’, also ‘rush’, geswing ‘a stroke with a weapon’, of Germanic origin; related to German schwingen ‘brandish’.

Swing means or implies, a motion or direction, or an oscillation. So therefore, "Swing" can also be applied to the use of a power level that varies, or swings from one level to another and returns.

So in essence - we are using one form of power to raise and lower a level of another - Amplitude can be thought of in this way as a rise and fall of a condition or region - an envelope.

 

[w9cll]

Now, look carefully...

Where is this directed?

 

[338_MtRushmore]

Real AM doesnt swing.

I'd love to hear an explanation for this.

 

[Highway Man]

That sombitch swinging like a swing set! DRIVER!!

 

[nomadradio]

CB linears tend to exaggerate the carrier from the radio, and fail to fully amplify the modulation peaks. An average-reading wattmeter will show the reading fall when you talk, or "backwards modulation". If this is bad enough, the audio quality suffers. The routine remedy is to reduce the radio's carrier power below its normal "barefoot" power level.

Do it right, and the carrier coming out of the amplifier will now once again match the peak modulated power and restore a more-natural sound to the audio.

Of course if a little is good more is better, right? This leads to turning the carrier way down, to make the wattmeter "kick" upwards with your voice audio in a satisfying way.

But the desire to retain the full peak power of the radio no matter the carrier level is generically called a "swing kit".

Since the modulator circuit used for AM is not the same in every radio, the specific circuit "trick" to achieve this is not the same for every radio.

In a simple radio like a Cobra 29, it can be as simple as a resistor with a capacitor in parallel with it.

The only reason on God's green earth to do this to a radio is for use with a linear. If you plan to use the radio alone, it's a wasted effort.

73

 

[Handy Andy]

Where is this directed?

Not anyone in particular, but references to "Swing" can be taken many different ways.

I was simply posting a definition I found quite humorous-the entire definition of Swing can be used as nearly a universal form of recognition of a simple toy for a child's playtime onto something more of a pendulum and timekeeping method,

To me, others don't see "swing" like I do, as a viable means or alternative method in which to communicate - since Swing can be anything thing from a Swing set, onto being used as a metaphor for World Series Playoffs and where to aim for in the Bleachers - the "Swings" we're playing with may oscillate - but they don't hold someone's butt up off the ground, they don't send balls flying into the air - but using a method for swing can offer a means to be heard when things pile-up - this too can be applied to being accountable for seating arrangements...but that requires a chair, it's safer than a swing. That's another thread...

 

[543_Dallas]

I'd love to hear an explanation for this.

If you use an average reading watt meter like a Bird 43 and the carrier is modulated 100% positive and negative with a single tone the meter will not swing. When you talk into the microphone it will have some wiggle but no crazy swing

 

[338_MtRushmore]

If you use an average reading watt meter like a Bird 43 and the carrier is modulated 100% positive and negative with a single tone the meter will not swing. When you talk into the microphone it will have some wiggle but no crazy swing

Sure, you can make a watt meter not swing by unplugging it too. Modulation itself is swing. FM swings, but a watt meter wont reveal any swing. Can't have modulation without something swinging.