Pill factory

[Onelasttime]

Now I don't claim to know anything about anything but I can imagine all the work that went into putting this together. The detail looks very good and if I built an amp I would want it to look like this even though the lid goes on I would know it. It would have to have a metal lid to keep the RF in right? I can't imagine how someone would go about matching all the double pill sections together. Or is it just "put it together and it is what it is"?

I would never want it to look like that! It is kind of like having a Battle Tank that looks tough versus one that is tough! Some of the fastest car's "exotics" look dreadful but they are fast and handle great! On the other hand their are all kinds of cars that look fast and sexy that are basically not fast and are just really pretty turds!

First I would not want that much wire in any amp I owned or built!

It is not about the money since anyone that would want a beast like that has to know it is not going to be cheap. That said the price parts is the same if it is a 1 transistor amp, 4 transistor amp or 32 transistor amp when looking at the unit price for each part.

I will not own anything that is not AB biased with delay,temp tracking bias, low impedance transistor feeding the bias etc....I am a sand bar resistor free zone with regards to biasing on bjt rf transistors. My principals and values will not allow me to own something designed and built with such slip shod design and construction methods. The time for that sort of poor design and construction is long since come and gone and people are just living in the past still. It is right up there with child brides in terms of how stupid and old fashioned it is! Maybe we should go back to other archaic stupid things like blood letting to cure disease! Maybe arsenic and brandy is a great health tonic for Olympic Marathon Runners! Maybe we should still be stoning people especially women or lighting them on fire because they shamed the family name by going out of the house with out a male family member to escort them! LOL It would be just as stupid as having a hand crank to start a modern car engine or solid rubber tires.

I buy machines mechanical or electronic to perform a function not to look at! Things designed just to be looked at and elicit an emotional response we call that art. Normally we place art on a wall or in a case and all you can do it look at it that is it's function.

 

[Onelasttime]

Yes matching is important but well documented.
Yes it all gets RF tight enclosures.
and
A candy store.
https://www.w6pql.com/parts_i_can_provide.htm

Ya gots ta pay ta play . Never said the high life was cheap.
What would you rather do ?
Four times the current at 14V with obsolete devices , at half again the IMD, at nearly four times the dissipated heat load?
And melt it down and build it back up repeatedly

Or

Spend it once and get it right.

I see it as a know brainer...

Yes I would have moved to LDMOS years ago if I did not have 12 or 14 PCB that cover 1, 2 and 4 transistor rf amps. Since I have those PCB's it would be silly for me to start over with LDMOS that and I really do not often use an amp and when I do It is normally a 1 or 2 transistor amp so gong to 50V or 65V LDMOS is a bit of a waste for me. Likewise I have enough high power triode and pentode tubes to build a nice tube base amp so that leaves me in kind of a no-mans-land situation.

All of that said LDMOS is the future today and unless you are like me and have a lot of parts in boxes it is definitely the smarter way to go today! NXP has some cool toys for sure!

 

[357]

Thanks for the pin!

 

[WINKDOGG]

kopcicle as always spot on with the technical info !

Its pretty amazing what the LDMOS can do , not to mention they are virtually indestructible! Ive seen them volted with full high power carriers into a piece of 6" cut off coax ! A builder I love keyed a 2 LDMOS box for 50 minutes straight unedited and was arcing the center strands to the shielding with a screwdriver making lightning(BBi videos on PoopTube) ! Awesome technology I hope to someday completely understand ! 1500 Bird watts with a 2 "pill" ldmos just cruising and keeping cool with tight harmonics and a reasonable amperage pull ! That was a fantasy a few years back ! I hope the prices drop and they start mass producing a semi affordable ldmos box for the masses !

Great info from everyone , Thanks guys and 73's !

Thats about right in price tech- nine used to be or is still on you tube he makes the best amps around.

Tech-Nine does build some screamers but the Hams don't see what we do in them Because we splatter all over 10meters when one gets volted and starts producing serious power lol . I get it I love the efficiency and crisp clean signal of an A or AB but something about a juicy dirty class C still gets me excited lol

"Class C is that dirty

Toshiba BJT's ? We're all chumps...
View attachment 23953 View attachment 23954 View attachment 23955

The first is a DC to 54 SDR @ 500mw
Next is it's 300w amplifier. Note the filter section.
Then the big brother 1.8-54 Mhz for 2xBLX188XR .

I'll spell it out in plain english.


Amplifier Class Description Conduction Angle
Class-A Full cycle 360o of Conduction θ = 2π
Class-B Half cycle 180o of Conduction θ = π
Class-AB Slightly more than 180o of conduction π < θ < 2π
Class-C Slightly less than 180o of conduction θ < π
Class-D to T ON-OFF non-linear switching θ = 0

Lets get some fundamental myth out of the way .
View attachment 23956


Solid-state amplifiers cannot be class "AB1" or class "AB2". A bipolar transistor amp cannot be a sub 1 or sub 2 class because they do not have grids to have or not have grid current. Solid-state amplifiers have bases or gates, and a bipolar transistor always has base current.

Class AB does not mean the amplifier is linear. "Linear" in the context of amplifiers indicates a linear transfer function, or a transfer function that has the proper transfer function curve shape to minimize odd-order intermodulation products. A linear transfer function generally means the output power level tracks the input power level in a way that does not cause excessive 3rd, 5th, 7th and other odd-order mixes. Only odd-order mixing or distortion produces annoying splatter.

The bias current can NOT remain steady because the bipolar requires a change in base current to produce a change in collect current.
If the bias current remains steady with varying drive, the amplifier will have gain compression.
If the VOLTAGE supplied to the bias system remains fixed at a level that produces the correct Ic for the device junction temperature, the amplifier will not gain compress when the exciter power rectified in the EB junction tries to add negative voltage back into the bias supply.
If the current is regulated, the bias will go negative as drive is increased.
That's why high power transistors can not be correctly biased without an active bias system that maintains constant voltage with a very low bias dynamic source impedance .
FET's, because they have no gate current (hopefully), require only
a regulated voltage source of almost any impedance.

I'd like to thank Tom Rauch and https://www.electronics-tutorials.ws/amplifier/amplifier-classes.html for the text and graphics
Sławomir Kleczyk for the photos.

I'd rather convert DC/DC to get the necessary voltage and use a modern output device .
Directive 2002/95/EC, originated in the European Union in 2002.
This was the initial death knell for the Toshiba 2SC2879. Production modifications were made within the year.
All applicable products in the EU market since July 1, 2006 must pass RoHS compliance. This killed 2SC2879.
Short version , lead free.
Long version Beryllium free.
Longer version is BJT's had outlived their design expectancy and the only market was HF radio. Toshiba threw in the towel and cut what was becoming a loss leader. This was sixteen years ago!
Then the imitators and outright fakes.

If you read this far I commend you because all this remedial education is putting me to sleep.

Bias is not resistors , diodes or even a fixed source .
Class of operation is determined by bias
BJT's are dead
LDMOS or MosFet
Damn I long for a time when tubes were a simple affair of a few volts here and there and a tank circuit out of the handbook.

As you were

girl mom can never meet , Class B she kinda likes and she wants you to marry A-B or better lol" A Quote from BBi The biggest Mud Duck in Idaho !!!

That's why I love these forums , (Most) hams know what we are doing and don't try to make us look bad for "running dirty" class C's !! I am respectful of my neighbors no matter how much fire is in the wire , after 25+ years I'm still happy with the factory 40 and upper and lowers I couldn't even tell you the last time I scanned my extras . And I have the tuner and bandwidth with my array to drop pretty low and get up pretty high on the bands I just like jawing on the freeband !

 

[Onelasttime]

C-class as I see? Bummer.

Nothing is a bigger waste of transistors than an amp that can not live and thrive on SSB!

 

[025]

I think TechNine only builds class C amplifiers. I've never seen one of his that had bias resistors installed .....

Where do the bias resistors go? How can i learn about this? Trying to understand the bias part. I thought it was done with a zener diode across the power in?

 

[nomadradio]

If there were a single authoritative book on the subject, I would recommend it.

Closest I can come would be Lou Franklin's two books "The Screwdriver Expert's Guide" and "Understanding and Repairing CB Radios".

There is a particular kind of enthusiasm I have seen over the years for this kind of info. Back in the 80s, it was folks who just wanted to know what parts to change and where. Didn't want to know why, just what steps to modify the radio for channels, more AM swing and such.

Fair enough. But you seem interested in the "why" of amplifier circuits, as much as the "how" of putting them together.

Here's a link to Lou's web site: http://cbcintl.com/

The principles that dictate the design of an amplifier also apply far beyond just that subject. Even if your interest is narrowed to just the subject of amplifiers, the underlying theory of how it (and other stuff) works is kinda necessary.

Lou's writing style is clear and to the point. Not sure how you would come to understand the amplifier if you don't also make sense of the radio attached to it.

73

 

[025]

If there were a single authoritative book on the subject, I would recommend it.

Closest I can come would be Lou Franklin's two books "The Screwdriver Expert's Guide" and "Understanding and Repairing CB Radios".

There is a particular kind of enthusiasm I have seen over the years for this kind of info. Back in the 80s, it was folks who just wanted to know what parts to change and where. Didn't want to know why, just what steps to modify the radio for channels, more AM swing and such.

Fair enough. But you seem interested in the "why" of amplifier circuits, as much as the "how" of putting them together.

Here's a link to Lou's web site: http://cbcintl.com/

The principles that dictate the design of an amplifier also apply far beyond just that subject. Even if your interest is narrowed to just the subject of amplifiers, the underlying theory of how it (and other stuff) works is kinda necessary.

Lou's writing style is clear and to the point. Not sure how you would come to understand the amplifier if you don't also make sense of the radio attached to it.

73

Definitely. I figured its hard to make something work if you dont understand why it works. At some point i want to build a few amplifiers. I passed my extra a few years back and realize I dont know crap!

 

[Onelasttime]

Personally, I think his construction is very well done. The B+ lead appears to be wrapped to secure it to the B+ rail before it was soldered. The negative cable is securely soldered to the ground plane. The resistors are mounted off the board on long leads to help promote air circulation and cooling. Exactly the way I would have done it.

OLT ... show us something you've built.

- 399

You really want to see some of the things I am working on?

How about an amp or two or in various stages of construction. I need more heat sink material and more individual components. Since I do not sell them I am not in a rush to buy more parts at this moment in time.

They are tiny compared to that and are not Manhattan style and not my design but I have built them with my own hands if that counts.

I have not worked much since Covid-19 and am not getting Unemployment either. This last year since I had Covid-19 last Feb. I have had some serious health issues. Slowly getting healthy again. It really made my diabetes bad.

Want to see a trumpet or two I have built and for sale? Any parts I have made for trumpets myself?

I have some rifle stocks in various stages from wood blanks to almost finished stocks.


That is definitely a Tech Nine build his name is in the upper left hand side by the top rail in black.

I am not into Class C transistor amps since I can not talk SSB on them.

Not into Manhattan style builds unless it is for prototyping! This is 2021 not 1971!

Not into mobile bipolar amps with that many expensive, rare, obsolete devices to achieve an output beyond the legal limit of ham use. I hate seeing amps built for the purpose of not actually communicating in a 2 way manner. This amp does not exist for actually talking and communicating with other humans on the radio!

No welding cables needed to power anything I build or use. I do have welding cables but I use them to actually weld things not power my transistor rf amp!

 

[Onelasttime]

Toshiba BJT's ? We're all chumps...
View attachment 23953 View attachment 23954 View attachment 23955

The first is a DC to 54 SDR @ 500mw
Next is it's 300w amplifier. Note the filter section.
Then the big brother 1.8-54 Mhz for 2xBLX188XR .

I'll spell it out in plain english.


Amplifier Class Description Conduction Angle
Class-A Full cycle 360o of Conduction θ = 2π
Class-B Half cycle 180o of Conduction θ = π
Class-AB Slightly more than 180o of conduction π < θ < 2π
Class-C Slightly less than 180o of conduction θ < π
Class-D to T ON-OFF non-linear switching θ = 0

Lets get some fundamental myth out of the way .
View attachment 23956


Solid-state amplifiers cannot be class "AB1" or class "AB2". A bipolar transistor amp cannot be a sub 1 or sub 2 class because they do not have grids to have or not have grid current. Solid-state amplifiers have bases or gates, and a bipolar transistor always has base current.

Class AB does not mean the amplifier is linear. "Linear" in the context of amplifiers indicates a linear transfer function, or a transfer function that has the proper transfer function curve shape to minimize odd-order intermodulation products. A linear transfer function generally means the output power level tracks the input power level in a way that does not cause excessive 3rd, 5th, 7th and other odd-order mixes. Only odd-order mixing or distortion produces annoying splatter.

The bias current can NOT remain steady because the bipolar requires a change in base current to produce a change in collect current.
If the bias current remains steady with varying drive, the amplifier will have gain compression.
If the VOLTAGE supplied to the bias system remains fixed at a level that produces the correct Ic for the device junction temperature, the amplifier will not gain compress when the exciter power rectified in the EB junction tries to add negative voltage back into the bias supply.
If the current is regulated, the bias will go negative as drive is increased.
That's why high power transistors can not be correctly biased without an active bias system that maintains constant voltage with a very low bias dynamic source impedance .
FET's, because they have no gate current (hopefully), require only
a regulated voltage source of almost any impedance.

I'd like to thank Tom Rauch and https://www.electronics-tutorials.ws/amplifier/amplifier-classes.html for the text and graphics
Sławomir Kleczyk for the photos.

I'd rather convert DC/DC to get the necessary voltage and use a modern output device .
Directive 2002/95/EC, originated in the European Union in 2002.
This was the initial death knell for the Toshiba 2SC2879. Production modifications were made within the year.
All applicable products in the EU market since July 1, 2006 must pass RoHS compliance. This killed 2SC2879.
Short version , lead free.
Long version Beryllium free.
Longer version is BJT's had outlived their design expectancy and the only market was HF radio. Toshiba threw in the towel and cut what was becoming a loss leader. This was sixteen years ago!
Then the imitators and outright fakes.

If you read this far I commend you because all this remedial education is putting me to sleep.

Bias is not resistors , diodes or even a fixed source .
Class of operation is determined by bias
BJT's are dead
LDMOS or MosFet
Damn I long for a time when tubes were a simple affair of a few volts here and there and a tank circuit out of the handbook.

As you were

Nice work!

 

[OldTech03]

Nice work!

I understand the above, but one of the hallmarks of the repair industry "at least where CB amps is concerned" I get as many as 150 amps a year to repair and turn away that many, and in my world the 2SC2879's the 2890's, the SD1446's the MRF455's, etc are KING!. We can discuss till the cows come home the shortcomings of the so-called fakes like the HG's we can even discuss if there is really any truth to the biasing concepts and if they are accurate but I have spent some time in the last several months with the HG's and have found that if I repair amps like the TEXAS STAR amps I have no choice but to spend some time understanding how to make them work as well as they can be made to work. I have repaired about 15 or more TS amps in the last several weeks with HG's and frankly have been happy with the results it took some tinkering around but the HG's are working well. Looking forward I'm sure the future of amp technology will certainly change but for the moment the real challenge isn't the design as much as it is can make the customer happy with my ability to make his pride and joy work like it should or maybe even better and right now that whole concept in the world of repair is totally reliant on the HG's. Like Electric cars I love the technology but I just want my old F-150 V8 running.

 

[freecell]

OldTech03 posted:

"in my world the 2SC2879's the 2890's, the SD1446's the MRF455's, etc are KING!"

you mean 2290's, right?

 

[OldTech03]

OldTech03 posted:

"in my world the 2SC2879's the 2890's, the SD1446's the MRF455's, etc are KING!"

you mean 2290's, right?

I did that on purpose to see if anyone would catch it. LOL!

 

[Onelasttime]

Personally, I think his construction is very well done. The B+ lead appears to be wrapped to secure it to the B+ rail before it was soldered. The negative cable is securely soldered to the ground plane. The resistors are mounted off the board on long leads to help promote air circulation and cooling. Exactly the way I would have done it.

OLT ... show us something you've built.

- 399

 

[Onelasttime]

I need to take a photo of my finished trumpet I lost the photo's on my last phone and did not know I did not have them backed up on my desk top.

I also lost images of my stocks from blanks to finished. I will try to put up some more.

I make a lot of things for myself but almost never post anything because I do not want to show off or be the center of attention.

Unit_399 asked me to share some things I have built. I do not often take photo's of things I am building or have built.

The trumpet valve assembly in the image is built by Huxon Gakki. The bell, braces, leadpipe were all drawn, hammered and turned by me with home made tooling. I have about 20 or 30 NOS vintage bells, 4 or 5 new modern production bells.

Nothing wrong with Tech 9's build quality! I just do not like the design or the wastefulness of the design. The reason why we do not have Toshiba 2SC2879's at affordable prices for the use of the hobby is because of wasteful and abusive designs like this that burn through transistors like a steam engine burns through coal. So I admit I am bitter that I have to use Chinese made bipolars because some people could not control their appetited and destructive and willful over consumption and abuse of a limited resource.

I should not have had to anticipate this and stockpile Toshiba's like my mother in-law canning venison and sauerkraut waiting for WWIII to hit! What are Toshiba's now $$$? They are unavailable from RF parts they were up to $260 a piece last I checked. Toshiba 2SC2290's are at $110 each as I type this at RF Parts!

So I am a bit bitter.