On 20 Sep 2006 06:56:50 -0700, "Telstar Electronics"
wrote:

+++Frank Gilliland wrote:
+++ That's because I don't make cheap, disposable crap. Never have, never
+++ will. But the use of FET's is at the discretion of the builder. The
+++ amp can be built with either FET's or bipolars. No other modifications
+++ are necessary, just a variation in the initial alignment.
+++
+++Let me get this straight...swapping FETs with bi-polars in the
+++design... and no modifications are necessary???
+++Get real... there are impedance matching issues, possibly B+ sources
+++level differences, as well as well as totally different biasing
+++circuitry. You are going to bias Frank?... right?
+++
+++www.telstar-electronics.com
***********

His modular design will allow for bias network to change versus
technology. Input/output impedances for bipolar and FETS do not differ
that much for equal power out and drive conditions. FETS do tend to be
slightly higher though. Also his output module should be adjustable
enough to compensate for these variances.

james

james wrote:
Prefer FETs even with their cost. They suffer less from thermal
runaway as bipolar designes do. Bias network is easier to design.

Major disadvantage to FETS are the inputs are very static sensitive.
SO some means of ESD protection is needed that wont h inder RF
performance.

But what about B+ requirements... power FETs are usually 28V or
higher... while the bipolar allows for mobile use at much lower
voltages. The FETs are also cost prohibitive as far as I'm concerned.

www.telstar-electronics.com

On Wed, 20 Sep 2006 15:00:51 GMT, james wrote
in :

On Tue, 19 Sep 2006 14:31:52 -0700, Frank Gilliland
wrote:

+++
+++Enough of that cheap one-board crap..... this amp is MODULAR!
+++
+++Modular design allows easy repair and modification, as well as ease of
+++construction and interchangeability between different amps. It also
+++allows seperation of functions both electronically and physically. The
+++modules include:
+++
+++* Input module. Includes variable attenuator and dummy load which
+++provides adjustment of input power without 'tweaking' anything inside
+++the radio.
+++
*************

An attenuator on the input is nice. I am not sure a variable one is
needed. By variable a multistep attenuator with four to six different
values of attenuation would be a sufficient. A capability to switch
the input drive to a internal du mmy load would nice luxury item but
not necessary.


There are two reasons for a variable attenuator. First, it allows the
user to adjust the input power to achieve the best output power for
the transistors being used. Second, the circuit is physically smaller
than a stepped attenuator. The dummy load can also be external if the
driver is more than a few watts.


+++* Control module. Board that controls keying, bias & cooling fan.
+++
+++* Sensor module. Board with circuits that take measurements from
+++various locations throughout the amp and sends them to a meter. Meter
+++function selection can be by rotory switch or by LCD display simply by
+++swapping the board (module). Meter functions may include:
+++
*****************

Man talk about monitoring circuits. Nice thing to have on a high tier
amp. In reality most of these are great for development and early
testing. Actual production would cause product cost to sky rocket.


The idea here is to show all the possibilities, not necessarily to
include all of them. Regardless, a sensor module could be built that
-does- include all of them. And the rest of the amp will be designed
with numerous test points that can easily be tapped for use by the
sensor module, or just used for occasional service and calibration.
There is one major advantage of having lots of measurements available
at the front panel: it provides an opportunity for non-technical users
to learn more about the internal operation of the amp, and therefore
the best way to use it. So it could be a great educational tool for a
classroom, or maybe even a ham.


snip
+++* Power Amplifier Module. The module will consist of the amplifier
+++circuit, heat sink and cooling fan, constructed inside an enclosed
+++sub-chassis designed for forced-air cooling. Flying in the face of
+++convention, the power amplifier circuit will -not- be mounted on a PC
+++board. Instead, the components will be chassis-wired with heavy-guage
+++copper, except for the transistors which will be wired with strips of
+++copper sheet having rounded edges and corners. This allows easy repair
+++and modification, as well as more secure and robust connections.
+++Circuit will be an ultra-linear, broadband, AB push-pull design
+++(details at a later date).
+++
****************

AIr dielectric striplines are nice for the power transistors. They do
introduce some memchanical issues.


Aint teflon great? It's almost too easy to drill a small hole in the
strip and mount a teflon standoff. Heck of a lot easier than trying to
design a board around the mounting feet. And strips allow a mechanical
connection to the flags that's better than filling the gap between the
flag and trace with solder.


Great if you are in the 2KW or more
output range. In the 100 to 250 watt range 2 ounce copper laminate
would be quite sufficient.


True, if you expect the transistors to never be replaced. But that's
not the reality with CB amps. The owners like to swap transistors for
more power. Either that, or they overdrive the transistors and blow
them up. Replacing them tears up the board, which is why it's hard to
find an old single-board amp with good traces. Point-to-point wiring
eliminates this problem because both the transistors -and- the strips
can be replaced. The servicable life of the amp is almost indefinite
irrespective of the amount of work done to it.


snip
If you really want to
go whole hog on the striplines then why not take the copper strips and
either silver or gold plate them.


Because it wouldn't last, and that's contrary to the concept behind
the amp.


Word of caution on gold over copper.
Nickel is not a good conductor of RF. Nickel is usually plated onto
copper to give gold a hard surface to plate to. Plating gold directly
onto copper requires a much thicker plating so that the copper will
not leach through the gold.


Gold plating onto copper or brass is best done on top of a layer or
two of silver. You can verify this with a call to your local trombone
repair shop.


snip
*********************

Man after designing such a high tier amp, you adjust the bias through
a panel hole with a screwdriver? Will you supply the gold plated
screwdriver?


It's not "high tier" at all. It's just moving the technology forward
about 20 years or so (with 20-30 years of catch-up still to go). The
boards are single-layer and can be fabricated at home with that cool
laser-printer transfer stuff, the individual components are common and
inexpensive (except maybe the power transistors), and the construction
is both simple and flexible. The only major expense (other than the
power transistors) is the labor. Just hire a few illegals and you have
yourself a business! Or build it yourself with all the gold-plated
frills and LCD sensor array if you want. Or build it one module at a
time. Or buy the basic model and modify the modules as needed. It's
all up to the builder. Yet despite all the possible variations, the
basic design remains constant. That's the great part about a modular
design.

On 20 Sep 2006 09:06:03 -0700, "Telstar Electronics"
wrote in
.com:


james wrote:
Prefer FETs even with their cost. They suffer less from thermal
runaway as bipolar designes do. Bias network is easier to design.

Major disadvantage to FETS are the inputs are very static sensitive.
SO some means of ESD protection is needed that wont h inder RF
performance.

But what about B+ requirements... power FETs are usually 28V or
higher... while the bipolar allows for mobile use at much lower
voltages.


Maybe you missed the part about the optional power supply. Go back and
read it again.


The FETs are also cost prohibitive as far as I'm concerned.


I'm not suprised.

Frank Gilliland wrote:
* Power supply module (optional). Power transistors that are designed
for higher voltage are more linear and -much- more reliable than those
designed to operate on 12-14 volts. This switching power supply bumps
up the voltage to 28 or 50 VDC and allows the use of such transistors.

Frank, just how much do you think this amp is going to cost? Sounds
like It's going to be out of this world with all the stuff you are
talking about...

www.telstar-electronics.com

On 20 Sep 2006 17:48:15 -0700, "Telstar Electronics"
wrote in
.com:

Frank Gilliland wrote:
* Power supply module (optional). Power transistors that are designed
for higher voltage are more linear and -much- more reliable than those
designed to operate on 12-14 volts. This switching power supply bumps
up the voltage to 28 or 50 VDC and allows the use of such transistors.

Frank, just how much do you think this amp is going to cost? Sounds
like It's going to be out of this world with all the stuff you are
talking about...


It will cost much more than you can afford on your budget, Brian. But
if you -really- want one just wait a few years and maybe they'll start
showing up at garage sales and thrift shops...... ok, probably not.
But you can dream, right?

Frank Gilliland wrote:
It will cost much more than you can afford on your budget, Brian. But
if you -really- want one just wait a few years and maybe they'll start
showing up at garage sales and thrift shops...... ok, probably not.
But you can dream, right?

I thought you were going to show me how to design a amp that was
superior to mine... and was a product that was easily manufactured,
repeatable, reliable, and profitable. Business-101 Frank. From what I
can see of your design concept so far... you should reply... "none of
the above"... LOL

www.telstar-electronics.com

On 21 Sep 2006 02:56:23 -0700, "Telstar Electronics"
wrote in
.com:

Frank Gilliland wrote:
It will cost much more than you can afford on your budget, Brian. But
if you -really- want one just wait a few years and maybe they'll start
showing up at garage sales and thrift shops...... ok, probably not.
But you can dream, right?

I thought you were going to show me how to design a amp that was
superior to mine... and was a product that was easily manufactured,
repeatable, reliable, and profitable. Business-101 Frank. From what I
can see of your design concept so far... you should reply... "none of
the above"... LOL


Repeatable -- Not only am I making the final design public, the entire
process is going to be public domain. You, OTOH, won't even release
your schematic for fear of constructive criticism.

Reliable -- In case you haven't been paying attention, the fundamental
concept of the design is longevity. These amps are going to be around
and working long after you and your amps are dead and buried.

Profitable -- I have saved the best for last. The -best- thing about a
modular design is that it is perfectly LEGAL!!!. I can manufacture and
market the chassis and modules independently under the premise that no
component, in and of itself, constitutes an amplifier. The only way
the government can touch this is if they outlaw every aspect of hobby
electronics and the sale of each and every component, which we all
know isn't going to happen (unless Bush declares a national emergency
right after the 2008 election, refuses to give up his office, and
installs a Republican dictatorship). There isn't one business-person
on the planet that wouldn't invest in a business that can open up an
entire market that was previously illegal. That, my friend, is called
"profitable".

But you go ahead and continue your work on your diminutive little amp,
knowing that your market is limited in both scope and time. Feel free
to waste your time on a product that will soon be without a market.
The only thing you have going for you is the price.... but then again,
have you done any market research lately? Do you know what people will
pay for a decent amp? Probably not. But I have.

So now that the cat's out of the bag, how hard are you going to fight
this? Or would you rather buy into it and make a ****load of money?
Feel free to email me with your answer.

Frank Gilliland wrote:
Repeatable -- Not only am I making the final design public, the entire
process is going to be public domain. You, OTOH, won't even release
your schematic for fear of constructive criticism.
**Your statement here has nothing to do with having a repeatable
design.**


Reliable -- In case you haven't been paying attention, the fundamental
concept of the design is longevity. These amps are going to be around
and working long after you and your amps are dead and buried.
**This is all talk right now. The fact that you will be using
components such as connectors for board-to-board interfacing does not
lend itself to high reliability.**


Profitable -- I have saved the best for last. The -best- thing about a
modular design is that it is perfectly LEGAL!!!. I can manufacture and
market the chassis and modules independently under the premise that no
component, in and of itself, constitutes an amplifier. The only way
the government can touch this is if they outlaw every aspect of hobby
electronics and the sale of each and every component, which we all
know isn't going to happen (unless Bush declares a national emergency
right after the 2008 election, refuses to give up his office, and
installs a Republican dictatorship). There isn't one business-person
on the planet that wouldn't invest in a business that can open up an
entire market that was previously illegal. That, my friend, is called
"profitable".
**Again, nothing but talk and very premature... you have no design yet
to base any profitability claims.**


www.telstar-electronics.com

On a sunny day (Thu, 21 Sep 2006 03:53:36 -0700) it happened Frank Gilliland
wrote in
:

knowing that your market is limited in both scope and time. Feel free
to waste your time on a product that will soon be without a market.
The only thing you have going for you is the price.... but then again,
have you done any market research lately? Do you know what people will
pay for a decent amp? Probably not. But I have.

So now that the cat's out of the bag, how hard are you going to fight
this? Or would you rather buy into it and make a ****load of money?
Feel free to email me with your answer.

There is a problem here with 'profit'.
I just had a look at where I bought some other stuff, what amplifiers
here go for:
100W MOSFET 42 Euro and 86 cent ( 54 $ and 44 cent).
500W 242 Euro and 93 cent (308 $ and 58 cent).
1000W 660 Euro and 15 cent (838 $ and 55 cent).

Will indeed be hard to make any $$$$ on 100W amps.
Not so different in the US I think, 1700W 650$:
http://www.amateurlinearamplifiers.c...ce=hotproducts

500W 329$
http://www.amateurlinearamplifiers.c...ce=hotproducts


I cannot make 100W for 54$, and I cannot make 1700W for 650$......
You have to count the hours too.

Telstar has been at it now for years.....
At 4$ profit per amplifier you'd have to sell zillions.
:-)

OTOH as a learning exercise making them was great.
Just that I stopped when they were at in the street with the radio car to
arrest me, spotted them just in time.... OK maybe I had some harmonics...
and one licensed amateur was upset.... when he did see me with those big
toobes.
'If I hear you I will turn you in'.
He was later overrun by a car IIRC.
It somehow strengthened my faith in God.
But that is all of the past, and not on 27MHz.

Honestly.
Damn are we honest today.