Topics

uBitx AGC mod

Diver Martin <diver.martin@...>
 

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

K9HZ <bill@...>
 

From “Harris” ?


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 Jan 2, 2018, at 11:53 PM, Diver Martin <diver.martin@...> wrote:

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
<agc_schematic.png>
<agc_layout.png>

Diver Martin <diver.martin@...>
 

Your guess is as good as mine.  Search for 'agc.pdf' under the Bitx20 groups.io page.   The built in PDF title is 'SYNOP', and is listed as 'Chapter 13, Harris'.  It was uploaded 1/5/2005 (which seems like an odd date...)

On Tue, Jan 2, 2018 at 11:00 PM, K9HZ <bill@...> wrote:
From “Harris” ?


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 Jan 2, 2018, at 11:53 PM, Diver Martin <diver.martin@...> wrote:

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
<agc_schematic.png>
<agc_layout.png>




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Diver Martin <diver.martin@...>
 

Finding the file without searching yields that it was uploaded by Hans Summers.

On Tue, Jan 2, 2018 at 11:11 PM, Martin Held <diver.martin@...> wrote:
Your guess is as good as mine.  Search for 'agc.pdf' under the Bitx20 groups.io page.   The built in PDF title is 'SYNOP', and is listed as 'Chapter 13, Harris'.  It was uploaded 1/5/2005 (which seems like an odd date...)

On Tue, Jan 2, 2018 at 11:00 PM, K9HZ <bill@...> wrote:
From “Harris” ?


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 Jan 2, 2018, at 11:53 PM, Diver Martin <diver.martin@...> wrote:

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
<agc_schematic.png>
<agc_layout.png>




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?



--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

William R Maxwell
 

1/4/2005 would have been more of an odd date, at least in those parts of the world that use dd/mm/yyyy format., as it would have been April Fools Day. Why is 1/5/2005 an odd date? Just curious, although I agree that a fuller citation would be useful.

Bill, VK7MX


On 3/01/2018 6:11 PM, Diver Martin wrote:
Your guess is as good as mine.  Search for 'agc.pdf' under the Bitx20 groups.io page.   The built in PDF title is 'SYNOP', and is listed as 'Chapter 13, Harris'.  It was uploaded 1/5/2005 (which seems like an odd date...)

On Tue, Jan 2, 2018 at 11:00 PM, K9HZ <bill@...> wrote:
From “Harris” ?


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 Jan 2, 2018, at 11:53 PM, Diver Martin <diver.martin@...> wrote:

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
<agc_schematic.png>
<agc_layout.png>



--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Diver Martin <diver.martin@...>
 

Sorry, mostly in that it was uploaded so long ago.  Going back on some of the groups messages though, I guess BitX has been around for quite some years... I had only thought of it as a recent thing up until now :) 

Okay, back under my rock I go...

On Tue, Jan 2, 2018 at 11:37 PM, William R Maxwell <wrmaxwell@...> wrote:

1/4/2005 would have been more of an odd date, at least in those parts of the world that use dd/mm/yyyy format., as it would have been April Fools Day. Why is 1/5/2005 an odd date? Just curious, although I agree that a fuller citation would be useful.

Bill, VK7MX


On 3/01/2018 6:11 PM, Diver Martin wrote:
Your guess is as good as mine.  Search for 'agc.pdf' under the Bitx20 groups.io page.   The built in PDF title is 'SYNOP', and is listed as 'Chapter 13, Harris'.  It was uploaded 1/5/2005 (which seems like an odd date...)

On Tue, Jan 2, 2018 at 11:00 PM, K9HZ <bill@...> wrote:
From “Harris” ?


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 Jan 2, 2018, at 11:53 PM, Diver Martin <diver.martin@...> wrote:

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
<agc_schematic.png>
<agc_layout.png>



--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Alan G4NMA
 

'Harris' appears to be Frank W Harris K0IYE.

Alan G4NMA
 

William R Maxwell
 

Ah, all now understood. Now to learn more about our mysterious Harris.

Bill, VK7MX


On 3/01/2018 6:39 PM, Diver Martin wrote:
Sorry, mostly in that it was uploaded so long ago.  Going back on some of the groups messages though, I guess BitX has been around for quite some years... I had only thought of it as a recent thing up until now :) 

Okay, back under my rock I go...

On Tue, Jan 2, 2018 at 11:37 PM, William R Maxwell <wrmaxwell@...> wrote:

1/4/2005 would have been more of an odd date, at least in those parts of the world that use dd/mm/yyyy format., as it would have been April Fools Day. Why is 1/5/2005 an odd date? Just curious, although I agree that a fuller citation would be useful.

Bill, VK7MX


On 3/01/2018 6:11 PM, Diver Martin wrote:
Your guess is as good as mine.  Search for 'agc.pdf' under the Bitx20 groups.io page.   The built in PDF title is 'SYNOP', and is listed as 'Chapter 13, Harris'.  It was uploaded 1/5/2005 (which seems like an odd date...)

On Tue, Jan 2, 2018 at 11:00 PM, K9HZ <bill@...> wrote:
From “Harris” ?


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 Jan 2, 2018, at 11:53 PM, Diver Martin <diver.martin@...> wrote:

Anyone here used the Harris AGC Circuit in a uBitx or bitx?  I was perusing the Bitx20 files for AGC ideas, and came across an 8-page portion of a book from 'Harris', that describes an AGC circuit. So... I naturally copied it verbatim, put it into a circuit block, and have it set and ready to go into my uBitx motherboard mod.  But, I'd like to do two things first.

1)  Anyone used a similar design?  Your design thoughts/etc please.
2) Build up a PCB of it (2-3 week turnaround) and test it out.

Before I do 2, I'd like your feedback on 1) please.

Thanks!

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
<agc_schematic.png>
<agc_layout.png>



--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

William R Maxwell
 

Ah, thankls.


On 3/01/2018 7:14 PM, Alan G4NMA wrote:
'Harris' appears to be Frank W Harris K0IYE.

ON7HC
 

Hi Martin,

Please read #32103 + 14 related messages.

It's a AGC developed by Jim, ND6P.  I build it some time ago and it's working like a charm !
The AGC is audio derived, but attenuates the RF input, using pin diodes. I've used it on my Bitx40 build. The AGC acts like in a commercially build radio :)
Could be interesting ...

Herman - ON7HC

chris gress <Chrisg0wfh@...>
 

Looking at that circuit is q4 & q5 have there emitter and collector wrong way round well that's how I see it chris

On 3 Jan 2018 13:02, "ON7HC" <herman.docx@...> wrote:
Hi Martin,

Please read #32103 + 14 related messages.

It's a AGC developed by Jim, ND6P.  I build it some time ago and it's working like a charm !
The AGC is audio derived, but attenuates the RF input, using pin diodes. I've used it on my Bitx40 build. The AGC acts like in a commercially build radio :)
Could be interesting ...

Herman - ON7HC

Diver Martin <diver.martin@...>
 

Herman ON7HC,

Interesting.  Maybe I'll have an AGC-off... my usual PCB vendor is $9.50 for 10x PCB's, but $18 shipping if I want fedex (HK Post $6 if I want to for the slow boat, or $12 for DHL if I want the packaged delivered to me Ace Ventura style...).  I'll look at the schematic a little more closely.  Might be able to use the variable attenuation part as the current IF amp has enough gain as-is in the uBitx... A hybrid of the two perhaps?

Chris:  They look correct to me, both in the original schematic and my version... Emitter towards ground (pin 2 on the SOT23 form of MMBT3904)...

On Wed, Jan 3, 2018 at 5:01 AM, ON7HC <herman.docx@...> wrote:
Hi Martin,

Please read #32103 + 14 related messages.

It's a AGC developed by Jim, ND6P.  I build it some time ago and it's working like a charm !
The AGC is audio derived, but attenuates the RF input, using pin diodes. I've used it on my Bitx40 build. The AGC acts like in a commercially build radio :)
Could be interesting ...

Herman - ON7HC




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Michael Hagen
 

Maybe this?

http://www.qrparci.org/wa0itp/chap13.pdf

Mike, WA6ISP



On 1/3/2018 2:02 AM, William R Maxwell wrote:

Ah, thankls.


On 3/01/2018 7:14 PM, Alan G4NMA wrote:
'Harris' appears to be Frank W Harris K0IYE.


-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Diver Martin <diver.martin@...>
 

*dingdingding* cool, thank you Mike!  Good to have a more solid source on that.  I've made sure to bookmark the particular link to the full book, and add a copy to my personal library.

I think tonight I'm also going to have to break out my copy of EMIRD, see if I can find anything else in there.

I'm not super-inspired to design my own AGC circuit for this mod, mostly would prefer to use something known / proven to work well :)  Plenty for future reference though...

On Wed, Jan 3, 2018 at 7:48 AM, Michael Hagen <motdog@...> wrote:

Maybe this?

http://www.qrparci.org/wa0itp/chap13.pdf

Mike, WA6ISP



On 1/3/2018 2:02 AM, William R Maxwell wrote:

Ah, thankls.


On 3/01/2018 7:14 PM, Alan G4NMA wrote:
'Harris' appears to be Frank W Harris K0IYE.


-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

chris gress <Chrisg0wfh@...>
 

Looking at that circuit emitter on q5/q4 going though inductor and resistor to RX vc RX vc I take is positive since when do you have collector to collector in each of the 2 transistors and both been non don't seam correct to me 

On 3 Jan 2018 15:48, "Michael Hagen" <motdog@...> wrote:

Maybe this?

http://www.qrparci.org/wa0itp/chap13.pdf

Mike, WA6ISP



On 1/3/2018 2:02 AM, William R Maxwell wrote:

Ah, thankls.


On 3/01/2018 7:14 PM, Alan G4NMA wrote:
'Harris' appears to be Frank W Harris K0IYE.


-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Ken
 

On Wed, Jan 3, 2018 at 10:58 AM, Diver Martin <diver.martin@...> wrote:
*dingdingding* cool, thank you Mike!  Good to have a more solid source on that.  I've made sure to bookmark the particular link to the full book, and add a copy to my personal library.

I think tonight I'm also going to have to break out my copy of EMIRD, see if I can find anything else in there.

I'm not super-inspired to design my own AGC circuit for this mod, mostly would prefer to use something known / proven to work well :)  Plenty for future reference though...

On Wed, Jan 3, 2018 at 7:48 AM, Michael Hagen <motdog@...> wrote:

Maybe this?

http://www.qrparci.org/wa0itp/chap13.pdf

Mike, WA6ISP



On 1/3/2018 2:02 AM, William R Maxwell wrote:

Ah, thankls.


On 3/01/2018 7:14 PM, Alan G4NMA wrote:
'Harris' appears to be Frank W Harris K0IYE.


-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?


Diver Martin <diver.martin@...>
 

Ah-hah Chris, I see what you're saying.  I think you're right.  For simplicity, assuming RX_V is 10V and ignore R20 (120ohm), base of Q5 is 5V, the emitter (should be collector) is 10V through T4.

Methinks this will be something to simulate in LTSpice :)  I will probably also need to adjust for a 45MHz IF, this is probably designed for 12MHz reading the rest of the chapter.

On Wed, Jan 3, 2018 at 8:03 AM, chris gress <Chrisg0wfh@...> wrote:
Looking at that circuit emitter on q5/q4 going though inductor and resistor to RX vc RX vc I take is positive since when do you have collector to collector in each of the 2 transistors and both been non don't seam correct to me 

On 3 Jan 2018 15:48, "Michael Hagen" <motdog@...> wrote:

Maybe this?

http://www.qrparci.org/wa0itp/chap13.pdf

Mike, WA6ISP



On 1/3/2018 2:02 AM, William R Maxwell wrote:

Ah, thankls.


On 3/01/2018 7:14 PM, Alan G4NMA wrote:
'Harris' appears to be Frank W Harris K0IYE.


-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?