Date   
Re: Compander AGC

Joe Street
 

Hi Steve

AGC is always an interesting topic.  A couple of years ago I set out to build something of an improved audio derived technique.  I ended up using a vactrol with the LED portion driven by PWM via a PIC micro which was sampling a fast averaged signal level.  It required piecewise linear interpolation because the response of the LED/LDR is not linear but I was able to use a table lookup which was quite small and could tailor the AGC threshold, slope, attack and decay to anything I wanted and the great part was that the audio path was a simple resistor divider with zero impact on audio fidelity. The response characteristics of the LDR in the vactrol lend themselves well to the application of audio derived AGC but the technique gets around the typical limitations (ie too slow a response due to the need to integrate several cycles of audio rather than the time needed for several cycles of RF which causes a pop)  Perhaps the idea is more than you are looking for in a simple rig but I just thought I'd mention.

Happy New Year
Joe ve3vxo

On Mon, Dec 30, 2019 at 8:22 PM Steven Weber <steve.kd1jv@...> wrote:

UPS came through and dropped off the compander chip this afternoon. For those of you who might be interested, the part number is NCY9100DW2G

 

It works great, but only one little problem. It wants to keep the output level at 2V p-p. That’s about  10X a comfortable level for headphones. It doesn’t like to drive headphones directly, but adding a series resistor cleans up the cross over the distortion.

 

So, one solution would be to just put a big enough series resistor to the headphones to get a 200 mV signal. But it takes a 200 mv p-p input signal before the AGC action kicks in. So, there would have to be a boat load of gain before the chip to arrive at the 200 mv input, just to knock it back down again.

 

It’s possible to reduce the gain of the AGC system, but not to increase it. Another possible solution could be to add an external gain stage to the loop. But I don’t have much real estate left to add more parts. The compander chip is in a 16 pin wide body package.

 

All in all, looked like a good idea, but as usual the devil is in the details. Good thing I only bought 10 of the chips.

 

Steve KD1JV

 

BTW, Happy New Year everyone. Better yet, have a Merry New Year !

 

Re: BlinkySWR progress

David Perry <bumbledp@...>
 

What's the price?  

David G4YVM 

Re: BlinkySWR progress

Vojtech Bubnik
 

I was doing some further loss measurements using my minivna, measuring through loss of a "tube" ferrite UNUN by K1RF back to back with:
1) another tube UNUN
2) resonant T50-6 4t:27t + compression mica trimmer
3) altoids L tuner by Steve KD1JV

1) another tube UNUN
40m loss 9% ... that is per single "tube" UNUN: ... /2 = 4.5%
30m loss 11.5% ... /2 = 5.7%
20m loss 12.7% ... /2 = 6.4%
Here loss increases with frequency, and for higher frequencies a compensation 100pF cap across the primary is recommended.

2) resonant T50-6 4t:27t + compression mica trimmer
40m: loss 6.5% for the tube and the resonant tuner
30m: loss 4.1%, this is lower number than for the two tubes back to back
20m: loss 6.7%

3) altoids L tuner by Steve KD1JV
40m: loss 5.2%
30m: loss 6.5%
20m: loss 10.3%
21MHz: loss 17.2%

All in all, the losses are below 10% for all tuners. The losses are lowest for the altoids L tuner and for the resonant tuner in a configuration, where the coils in the tuners perform at their high Q. The resonant tuner efficiency seems to suffer at 40m due to low primary magnetizing inductance I suppose, but the efficiency of the resonant tuner raises at higher frequencies. The Altoids L tuner performs superb at 40m, as the T37-2 4uH core performs at its relatively high Q, but it suffers at higher frequencies, where the -2 material's losses are high. The ferrite tubes work OK at 40-20m and there is no tuning to it, its efficiency on 40-20m is worse than of the other tuners though. With the "BlinkySWR" circuit, there will be no questioning in the field, whether your antenna configuration is all right or not for the untuned UNUN, while the Altoids L tuner offers many degrees of freedom and the resonant tuner offers at least some degrees of freedom to adjust the tuner at non-ideal antenna lengths and configurations.

I am not sure how many kits shall we produce, maybe 50 pieces initially. We are still left with boards and parts for around 5 pieces, so we may give out two or three for free to get a feedback on useful configurations tuner configurations and examples of mechanical builds. I suffer from perfectionism, so I like the device to work perfectly with high accuracy, low losses, small size and easy use, but that is a high goal. Help and ideas are welcome to achieve that goal.

73, Vojtech OK1IAK



On Tue, Dec 31, 2019 at 8:55 AM David Perry <bumbledp@...> wrote:
You ask for the bands you should cover...I think most euro portable upside 40,30,20m.  Some americans it seems to me use 17,15 and 10 but in think, THINK, that if you catered for 40,30,20 you'd cover 90 percent of all users.

It sounds a fun project so I'm looking forward to building one

David G4YVM 

Re: Compander AGC

David Perry <bumbledp@...>
 

Interesting Steve.  Takes me back to the old 'no volume' xtal  set days...

David G4YVM 

Re: BlinkySWR progress

David Perry <bumbledp@...>
 

You ask for the bands you should cover...I think most euro portable upside 40,30,20m.  Some americans it seems to me use 17,15 and 10 but in think, THINK, that if you catered for 40,30,20 you'd cover 90 percent of all users.

It sounds a fun project so I'm looking forward to building one

David G4YVM 

Re: Compander AGC

Steven Weber
 

Well, it seems I can make this compander chip do the job after all. I increased the gain up stream and put a 220 ohm resistor in series with the headphones. The AGC kicks in at about 50 uV, a S9 signal. The 220 ohm resistor limits the volume to a reasonable level.

 

So, it looks like I can eliminate the volume control all together and the LM386 amp.

 

Steve KD1JV

 

 

Re: Compander AGC

Steven Weber
 

Yea, man I need new glasses 😊

 

 

NCY9100DWR2G  maybe?

 

> On Dec 30, 2019, at 7:22 PM, Steven Weber <steve.kd1jv@...> wrote:

>

> NCY9100DW2G

 

 

 

Re: Compander AGC

Larry KA5T
 

NCY9100DWR2G maybe?

On Dec 30, 2019, at 7:22 PM, Steven Weber <steve.kd1jv@...> wrote:

NCY9100DW2G

Compander AGC

Steven Weber
 

UPS came through and dropped off the compander chip this afternoon. For those of you who might be interested, the part number is NCY9100DW2G

 

It works great, but only one little problem. It wants to keep the output level at 2V p-p. That’s about  10X a comfortable level for headphones. It doesn’t like to drive headphones directly, but adding a series resistor cleans up the cross over the distortion.

 

So, one solution would be to just put a big enough series resistor to the headphones to get a 200 mV signal. But it takes a 200 mv p-p input signal before the AGC action kicks in. So, there would have to be a boat load of gain before the chip to arrive at the 200 mv input, just to knock it back down again.

 

It’s possible to reduce the gain of the AGC system, but not to increase it. Another possible solution could be to add an external gain stage to the loop. But I don’t have much real estate left to add more parts. The compander chip is in a 16 pin wide body package.

 

All in all, looked like a good idea, but as usual the devil is in the details. Good thing I only bought 10 of the chips.

 

Steve KD1JV

 

BTW, Happy New Year everyone. Better yet, have a Merry New Year !

 

Re: BlinkySWR progress

Vojtech Bubnik
 

Oh my, why is the groups.io shrinking the attached images so much? Is there a way to control the resolution of images atached?

BlinkySWR progress

Vojtech Bubnik
 

I hope Steve would not mind if I hijack his group to report on my progress of the BlinkySWR.

https://github.com/bubnikv/BlinkySWR
https://github.com/bubnikv/BlinkySWR/tree/master/kicad
https://github.com/bubnikv/BlinkySWR/tree/master/design

The BlinkySWR is an open source, open hardware accurate SWR and power meter, powered from the transceiver, no batteries.
The firmware is ready, now we are polishing the board.

We are considering to keep the BlinkySWR an experimenter's platform, so it could either be used as a stand-alone SWR meter, or a SWR meter with a tuner. The board should be versatile enough to support resonant EFHW tuner configuration and untuned UNUN, both with jumpers for switching the transformer ratio, and with optional jumpers for adding fixed parallel capacitors to the resonant tuner, which is handy in case a thin polyvaricon or a mica compression trimmer is used.

Getting ready for the summer, I am now testing an UNUN design by Steve Dick, K1RF, see the first line on page 25 of 
http://gnarc.org/wp-content/uploads/The-End-Fed-Half-Wave-Antenna.pdf
https://groups.io/g/qrp-tech/attachment/18190/0/45510996_10215818923279402_2807407408844898304_o.jpg

As seen on the attached pictures, I am measuring through loss when the UNUN by K1RF is connected back to back to a resonant EFHW tuner. The first is more lossy than the second. The measured losses are following:

40m: 10.3% loss for both tuners in series, so maximum loss for the K1RF tuner is lower than 10%.
30m: 7.7% loss for both tuners in series 
20m: 9% loss

I could do some more measurements with two K1RF UNUNS back to back or with two resonant tuners back to back resonated with a polyvaricon, but as of now it seems that the loss of a single tuner will not be higher than 10%. Now I am curious on how to shrink that thing down and to add some degrees of freedom to cope with the nature not cooperating (producing different impedances in the field than on my back yard).

We plan to run a series of 100 kits, SMDs pre-soldered. It will take shorter time to OK1TRP to program the assembly line than us to kit the parts, hi. We wil likely drop the ferrite tube recommended by K1RF + T50-6 core, so you could pick between the resonant and non-resonant EFHW tuner configuration. For the resonant tuner, you would have to source the polyvaricon or compression mica trimmer yourself.

We welcome suggestions on the tuner configuration, supported bands, cores and their windings, tunable capacitors etc. We hope that the community will provide useful feedback, so we would be able to update the manual along the way.

73, Vojtech OK1IAK
 

Re: Yet Another Single Band Transceiver (YASBT)

Steven Weber
 

Interesting, but you still need to develop an AGC signal from somewhere.

 

Hopefully UPS will make it thru the winter storm raging outside and deliver the ON semi Compander chip I ordered. It can be configured as an AGC and has a 20 ma output stage so might be able to drive headphones directly.

 

It does look to be an obsolete part (The ON semi web site doesn’t think it exists, yet the Mouser data sheet link works) but Mouser has 970 of them in stock. I may have to buy a bunch of them before they disappear.  These cost 87 cents and the closest replacement costs $5.70.

 

Steve KD1JV

 

 

   Found this on another forum.....

 

Re: Yet Another Single Band Transceiver (YASBT)

Vojtech Bubnik
 

IMHO regulating volume by DC saturating a ferrite core will first cause the ferrite to act as a non-linear device, second it will require considerable DC current, not compatible with battery power.


On Mon, Dec 30, 2019 at 4:26 PM poikaa3 <poikaarod@...> wrote:
   Found this on another forum.....

Re: ATS-V5

simon_hotchin@...
 

Looks awesome to me.  If there is a list, count me in.

Simon, KK6ODM

Re: Yet Another Single Band Transceiver (YASBT)

poikaa3
 

   Found this on another forum.....

Re: Yet Another Single Band Transceiver (YASBT)

Stan N8HN
 

Hey Steve,

If there actually is a list for interested purchasers your tracking put me on it please. Sounds awesome!

Thanks,

Stan-N8HN

Re: Palm Pico Paddle

dyerhard1972
 

Ha damn auto correct te ne key.
Jeff Ke4fwe  



Sent from my Samsung Galaxy smartphone.

-------- Original message --------
From: "dyerhard1972 via Groups.Io" <Dyerhard1972@...>
Date: 12/27/19 2:29 AM (GMT-05:00)
To: kd1jvdesigns@groups.io
Subject: Re: [kd1jvdesigns] Palm Pico Paddle

I have a te news key it works well.
Jeff Ke4fwe 



Sent from my Samsung Galaxy smartphone.

-------- Original message --------
From: "Mark Janzer via Groups.Io" <k5mgj@...>
Date: 12/26/19 12:33 PM (GMT-05:00)
To: kd1jvdesigns@groups.io
Subject: Re: [kd1jvdesigns] Palm Pico Paddle

The micro paddle shown is a tiny Te Ne Ke that the Ottawa club still sells in a larger size.

73
Mark
K5MGJ

Re: Palm Pico Paddle

dyerhard1972
 

I have a te news key it works well.
Jeff Ke4fwe 



Sent from my Samsung Galaxy smartphone.

-------- Original message --------
From: "Mark Janzer via Groups.Io" <k5mgj@...>
Date: 12/26/19 12:33 PM (GMT-05:00)
To: kd1jvdesigns@groups.io
Subject: Re: [kd1jvdesigns] Palm Pico Paddle

The micro paddle shown is a tiny Te Ne Ke that the Ottawa club still sells in a larger size.

73
Mark
K5MGJ

Re: Palm Pico Paddle

Stephen Wandling
 

Finally found the current Te Ne Ke here:


I agree this is much different than the one I got from Boyd.

VE7NSD
Stephen

On Thu, Dec 26, 2019, 11:29 AM John Evans, <john.evans.n0hj@...> wrote:
So it’s the same key only different.  LOL.  To me they are very different.

73 - John - n0hj

On Thu, Dec 26, 2019 at 10:33 AM Mark Janzer via Groups.Io <k5mgj=yahoo.com@groups.io> wrote:
The micro paddle shown is a tiny Te Ne Ke that the Ottawa club still sells in a larger size.

73
Mark

Re: ATS-V5

Steven Weber
 

Knobs take up space, rise the profile of the device and can get snagged on stuff. But they have advantages like easy and intuitive to use. It’s all about trade offs.

 

Steve KD1JV

 

Why are rotary adjustments not well suited?  I've often wondered about this feature.

David G4YVM 

_._,_._,_