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Variable power control


Walter
 

Could you provide the number of the transistor?  Yes, I am that needed.  LOL

Thanks


Walter
 

Also I cannot read the values of the Caps due to pixelation.  Could you provided those values.


K9HZ <bill@...>
 

Yeah that works. 


Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton - J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com


email:  bill@...

 


On Feb 21, 2018, at 12:48 PM, LKNDAVE via Groups.Io <novatronix@...> wrote:

THE ZENERS SET THE PASS VOLTAGE OF THE 100 VOLT 10 AMP DARLINGTON. sorry caps lock. they are 1 amp devices but the transistor slaves them to 10 amp handling. i have used this ciruit fo over 40 years. tayda has most of the parts, total like 5 bucks plus cheap shipping. read notes on schem. this is a 2 voltage control. my crappy software didnt have 4 position rotaries but most will get the idea. the transistor also has reverse emf diode built in.
dave<SERIESPASS.bmp>


LKNDAVE
 

one or the other. the object is to noy let the base of the transistor float. tayda make before break 3/4 position .089 $ each. no 10k needed.


LKNDAVE
 

parts:
q- tip142 $ 1.26 each
l1,2- 100 uh power inductor 
c1,2 - 100 ufd @ 50 vdc $.12 each
sw- your pick. rotary make before break 3 -5 pos depending how many levels you want .$.89 EACH
R1 1K 1/2 WATT -$.25 FOR 10
IF TOGGLE SPST USED LIKE SCHEMATIC THEN 10K 1/4 WATT.
PERF, VERO 
ZENER DIODES FROM THE 1N47XX SERIES $.04 EACH.
IF YOU WANT 5 VOLTS GET 1N4734 5.6 VOLT
9.3 VOLT USE 1N4740 10 VOLT.
ETC
DAVE


LKNDAVE
 


LKNDAVE
 

SUBTRACT A FEW PARTS AND A POT AND IT IS CONSTANTLY VARIABLE ADD ASC712 TO MONITOR CURRENT AND A VOLTAGE DIVIDER TO SEE WHATs GOING WITH REALTIME DETAIL.
DAVE
Ihate caps lock


Nick VK4PP
 

What about replacing RV1 with an AD5246, and an SWR bridge to monitor output power and then a PID loop to adjust drive level to attain desired output...


Walter
 

Thank you very much.

I have ordered the parts and will build this to add to my ubitx.

I think this will supply power to the PA power wire on the power connector.  Is this correct?

Do I need to do anything with RV1?

I will have my Watt/SWR meter on the ubitx so I will know what my actual power output is.

Would you be able to post an PDF or Jpeg of your print?  The print on this blog is not very clear.

I very much appreciate your help.

73, W9KJO, Walter


LKNDAVE
 

my software, expresssch only puts out .bmp i will look at doing something about the quality asap.
sorry for the poor quality.
dave
no changes the i can think of to rv1


LKNDAVE
 

i did the hokie pokie and this jpg came out


Thomas Sharka
 

What if you replaced the diodes with an LM317? Would that be as reliable?
 


Sent from Yahoo Mail. Get the app


On Wednesday, February 21, 2018 9:23 PM, LKNDAVE via Groups.Io <novatronix@...> wrote:


i did the hokie pokie and this jpg came out




Walter
 

Thank you very much

That is a very nice schematic drawing and readable

Thank you,  I cant wait to get the parts and build it.

73, W9KJO, Walter


Roberto Vannucci
 


I want to suggest a circuit that I have tested to regulate the power in my previous self-built HF transmitter. It is based on an HSMP3816 QUAD PIN DIODE.
I enclose the circuit file 73 IK6BLO

2018-02-22 9:33 GMT+01:00 Walter <W9KJO@...>:

Thank you very much

That is a very nice schematic drawing and readable

Thank you,  I cant wait to get the parts and build it.

73, W9KJO, Walter



Gordon Gibby <ggibby@...>
 

Thank you very much! I learned something from that.  Do you have any idea what is the minimum insertion loss?


On Feb 22, 2018, at 06:50, Roberto Vannucci <robertovannucci128@...> wrote:


I want to suggest a circuit that I have tested to regulate the power in my previous self-built HF transmitter. It is based on an HSMP3816 QUAD PIN DIODE.
I enclose the circuit file 73 IK6BLO

2018-02-22 9:33 GMT+01:00 Walter <W9KJO@...>:
Thank you very much

That is a very nice schematic drawing and readable

Thank you,  I cant wait to get the parts and build it.

73, W9KJO, Walter


<ss.bmp>


Karl Heinz Kremer, K5KHK
 

There is an HP application note about PIN diode attenuators: http://www.hp.woodshot.com/hprfhelp/4_downld/lit/diodelit/an1048.pdf

I was just about to recommend a PIN diode attenuator as well. The device used in this particular configuration reached it's end of life, and may be hard to get soon. There are alternatives: 

https://www.nxp.com/docs/en/data-sheet/BAP70Q.pdf

The data sheet has a chart that shows insertion loss based on frequency and control voltage. 
--
Karl Heinz - K5KHK


Gordon Gibby <ggibby@...>
 

​Thanks -- great info.  3db insertionloss.  



From: BITX20@groups.io <BITX20@groups.io> on behalf of Karl Heinz Kremer, K5KHK <khk@...>
Sent: Thursday, February 22, 2018 9:34 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Variable power control
 
There is an HP application note about PIN diode attenuators: http://www.hp.woodshot.com/hprfhelp/4_downld/lit/diodelit/an1048.pdf

I was just about to recommend a PIN diode attenuator as well. The device used in this particular configuration reached it's end of life, and may be hard to get soon. There are alternatives: 

https://www.nxp.com/docs/en/data-sheet/BAP70Q.pdf

The data sheet has a chart that shows insertion loss based on frequency and control voltage. 
--
Karl Heinz - K5KHK


Jerry Gaffke
 

Here's an old thread well worth reading that touches on pin diode attenuators, mostly in regard to agc for the receiver.
    https://groups.io/g/BITX20/topic/5945215
Here's another old thread:
    https://groups.io/g/BITX20/topic/5913954

Jerry, KE7ER


On Thu, Feb 22, 2018 at 06:34 am, Karl Heinz Kremer, K5KHK wrote:
There is an HP application note about PIN diode attenuators: http://www.hp.woodshot.com/hprfhelp/4_downld/lit/diodelit/an1048.pdf

I was just about to recommend a PIN diode attenuator as well. The device used in this particular configuration reached it's end of life, and may be hard to get soon. There are alternatives: 

https://www.nxp.com/docs/en/data-sheet/BAP70Q.pdf

The data sheet has a chart that shows insertion loss based on frequency and control voltage. 
--


LKNDAVE
 

Here is a pot controled version of my original zener power control. since i am an anti-rail go i added high limit and lo limit resistors. 
when i was young i persued a second class commercial operators license. in the log everyday the on air guy had to write down plate voltage and current. those 2 multiplie provided the FCC required station wattage. that was at the transmitter  so swr, connector, and line loss were not factored. P=I x E. this was not the RF OUT or the effective radiated power.  
i will be adding a simple accuate circuit add on to this to report voltage and current supplied to the output stage using 2 analog inputs to my system health display.
dave N4LKN


Walter
 

Very nice and helpful.  I will save this.

So, you seem to be saying that anything under 4.6volts is too low?

Will you system health display show on your current LCD display?  How will it input into the processor?

Thank you again.
--
73, W9KJO
Walter