Date   
Re: Replacing the Rotary Encoder #ubitx

Walter
 

If one wanted to lock out the rotary encoder, like some rigs which have a lock button for their tuner.

Could one just break one of the encoder lines with a switch, say the ground wire, and get the effect of locking to tuner?

73 W9KJO

Re: RD16HHF1 in the uBITX #ubitx

RCBoatGuy
 

OK, stupid question time. 

Let me preface this by saying that although I'm a EE, I've only recently gotten my Technician's license, and I've done nothing but digital design since taking my solid-state amplifier course 30 years ago.  So I don't know a lot about RF design, and what I did know I've likely forgotten...

That being said, I ran across this web page earlier today: https://www.sv1afn.com/rfattenuator.html .   This design uses a 6-bit, 50 ohm, 1-4000 MHz digital RF attenuator chip from Peregrine Semiconductor to vary RF attenuation from 0dB to 31.5dB in 0.5dB steps via an SPI serial interface.  Could we place something like this in between two of the earlier uBitX TX gain stages and use this to control our TX drive level digitally rather than using RV1 alone?  The newer PE4312 chip (the replacement for the obsolete PE4306 used in the design above) goes for less than $5 in small quantities (less than 100 units).

Please note from the PE4312 datasheet (http://www.psemi.com/pdf/datasheets/pe4312ds.pdf) that the maximum allowed input RF power is much lower for HF frequencies, going from roughly 11.5db @ 1MHz to about 23.5dB @ 50MHz (see Figure 4).  The PE4312 also allows control via a parallel interface for those that would rather control it that way, perhaps using an I2C digital I/O expander chip to control the attenuation rather than using SPI to save pins on the Raduino.

73,

Carl, K0MWC

Re: Connectors

Arvo W0VRA
 

The style is KF2510.

Re: RD16HHF1 in the uBITX #ubitx

Jerry Gaffke
 

Excellent find!
Power into Q90 of the uBitx is less than 1dBm (best guess, perhaps -7dBm?) and at 50 ohms.
The stage at Q90 might have a gain of 15dBm, I'm not sure without checking my simulation.
So this attenuator would never see 10dBm, spec says absolute max (where damage occurs) is +30dBm  = 1 Watt.

I think I'd leave RV1 in place to set max power, and then place this attenuator between RV1 and C84.
Assuming it works well with impedances that are in the ballpark but not exactly 50 ohms.

Disclaimer:  I'm a digital guy too.

Jerry, KE7ER


On Tue, Feb 20, 2018 at 11:40 am, RCBoatGuy wrote:
I ran across this web page earlier today: https://www.sv1afn.com/rfattenuator.html .   This design uses a 6-bit, 50 ohm, 1-4000 MHz digital RF attenuator chip from Peregrine Semiconductor to vary RF attenuation from 0dB to 31.5dB in 0.5dB steps via an SPI serial interface.  Could we place something like this in between two of the earlier uBitX TX gain stages and use this to control our TX drive level digitally rather than using RV1 alone?  The newer PE4312 chip (the replacement for the obsolete PE4306 used in the design above) goes for less than $5 in small quantities (less than 100 units).

Please note from the PE4312 datasheet (http://www.psemi.com/pdf/datasheets/pe4312ds.pdf) that the maximum allowed input RF power is much lower for HF frequencies, going from roughly 11.5db @ 1MHz to about 23.5dB @ 50MHz (see Figure 4).  The PE4312 also allows control via a parallel interface for those that would rather control it that way, perhaps using an I2C digital I/O expander chip to control the attenuation rather than using SPI to save pins on the Raduino.

Re: Raduino Replacemnt, COMING SOON!

Nick VK4PP
 

Hi Jerry
I am happy for others to use the Gerber's, but idd say let me actually order and test a batch first, then you can go crazy, just leave my callsign on the board.... Otherwise I am happy. O am not doing the for any profit, just for the greater Ham good...

I am thinking just Australia Post via eBay(paypal) listing. Board cost,(AU$1-2) + AU$3.50 post for international. And VK orders will be $1.xx for post...

73 VK4PLN

Re: RD16HHF1 in the uBITX #ubitx

K9HZ <bill@...>
 

Yep. There is a similar AD8367 that has a larger attenuation range... 45dB that can work too.  Just need to add it to the list.


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 20, 2018, at 1:40 PM, RCBoatGuy via Groups.Io <ijnfan-HamRadio@...> wrote:

OK, stupid question time. 

Let me preface this by saying that although I'm a EE, I've only recently gotten my Technician's license, and I've done nothing but digital design since taking my solid-state amplifier course 30 years ago.  So I don't know a lot about RF design, and what I did know I've likely forgotten...

That being said, I ran across this web page earlier today: https://www.sv1afn.com/rfattenuator.html .   This design uses a 6-bit, 50 ohm, 1-4000 MHz digital RF attenuator chip from Peregrine Semiconductor to vary RF attenuation from 0dB to 31.5dB in 0.5dB steps via an SPI serial interface.  Could we place something like this in between two of the earlier uBitX TX gain stages and use this to control our TX drive level digitally rather than using RV1 alone?  The newer PE4312 chip (the replacement for the obsolete PE4306 used in the design above) goes for less than $5 in small quantities (less than 100 units).

Please note from the PE4312 datasheet (http://www.psemi.com/pdf/datasheets/pe4312ds.pdf) that the maximum allowed input RF power is much lower for HF frequencies, going from roughly 11.5db @ 1MHz to about 23.5dB @ 50MHz (see Figure 4).  The PE4312 also allows control via a parallel interface for those that would rather control it that way, perhaps using an I2C digital I/O expander chip to control the attenuation rather than using SPI to save pins on the Raduino.

73,

Carl, K0MWC

Re: RD16HHF1 in the uBITX #ubitx

Joe Puma
 

SV1AFN makes some great products 

That’s all I can add here lol 

Joe,
KD2NFC 



On Feb 20, 2018, at 2:40 PM, RCBoatGuy via Groups.Io <ijnfan-HamRadio@...> wrote:

OK, stupid question time. 

Let me preface this by saying that although I'm a EE, I've only recently gotten my Technician's license, and I've done nothing but digital design since taking my solid-state amplifier course 30 years ago.  So I don't know a lot about RF design, and what I did know I've likely forgotten...

That being said, I ran across this web page earlier today: https://www.sv1afn.com/rfattenuator.html .   This design uses a 6-bit, 50 ohm, 1-4000 MHz digital RF attenuator chip from Peregrine Semiconductor to vary RF attenuation from 0dB to 31.5dB in 0.5dB steps via an SPI serial interface.  Could we place something like this in between two of the earlier uBitX TX gain stages and use this to control our TX drive level digitally rather than using RV1 alone?  The newer PE4312 chip (the replacement for the obsolete PE4306 used in the design above) goes for less than $5 in small quantities (less than 100 units).

Please note from the PE4312 datasheet (http://www.psemi.com/pdf/datasheets/pe4312ds.pdf) that the maximum allowed input RF power is much lower for HF frequencies, going from roughly 11.5db @ 1MHz to about 23.5dB @ 50MHz (see Figure 4).  The PE4312 also allows control via a parallel interface for those that would rather control it that way, perhaps using an I2C digital I/O expander chip to control the attenuation rather than using SPI to save pins on the Raduino.

73,

Carl, K0MWC

Re: [SPAM] Re: [BITX20] RD16HHF1 in the uBITX #ubitx

Lawrence Galea
 

Thanks
That seems to be better.
So all one would to even out the power is to change C93 and C94 and put a a 110pf across T11 primary.
Thanks
Lawrence

On Tue, Feb 20, 2018 at 3:46 AM, K9HZ <bill@...> wrote:

50 nF seems to be optimal… but it also needs the compensator across T11 primary of 110 pf…   Roughly 22 watts on all bands except 6 meters where the power is 13 watts.

 

 

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

Like us on Facebook! facebook icon

 

Moderator – North American QRO Yahoo Group.

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Lawrence Galea
Sent: Monday, February 19, 2018 11:36 AM
To: BITX20@groups.io
Subject: Re: [SPAM] Re: [BITX20] RD16HHF1 in the uBITX #ubitx

 

Hi,

I just unpacked my μbitx to check what was supplied and no time yet to hook it up.

Just a thought on the output power drop.

Can you try simulating reducing C93 and C94 so that with the corresponding higher reactance at lower frequencies less drive will be available at lower frequencies.

A value could be found to more or less even out the drive across the frequency range since the gate capacitance higher reactance at lower frequencies will compensate for the increased capacitive reactance of C93 and C94 while on the higher frequencies the opposite will be true.

Regards

Lawrence

 

On Mon, Feb 19, 2018 at 4:35 PM, K9HZ <bill@...> wrote:

> I did find the following in my simulations though... if you change R85 from 100 to 470 ohms (pre-driver stage bias), change R261 and R262 from 100 to 1K ohm, run RV1 wide open (full drive) and then use a compensating capacitor (your 33pf at 14 MHz) across T11 primary with a 1:4 transformer:

> 6M - 48pf

> 10M - 110pf

> 20M - 320pf

> 40M - 680pf

> 80M - 1,500pf

> 160M - 4,700pf

> It shows at least 20 watts out on each band except for 6 meters... where it peaks at 12 watts.

 

 

 

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

Like us on Facebook! facebook icon

 

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Gordon Gibby
Sent: Saturday, February 17, 2018 6:54 PM
To: BITX20@groups.io
Subject: Re: [BITX20] RD16HHF1 in the uBITX #ubitx

 

​Dr. Schmidt -- no way to put some feedback into the circuit in some manner to stabilize the gain?    1000 pf across the 22 ohm emitter resistors to have a 3db break at 7 MHz?

 

 


 


Virus-free. www.avg.com


Re: Replacing the Rotary Encoder #ubitx

Jack, W8TEE
 

It could also be done in software.

Jack, W8TEE



From: Walter <W9KJO@...>
To: BITX20@groups.io
Sent: Tuesday, February 20, 2018 2:38 PM
Subject: Re: [BITX20] Replacing the Rotary Encoder #ubitx

If one wanted to lock out the rotary encoder, like some rigs which have a lock button for their tuner.

Could one just break one of the encoder lines with a switch, say the ground wire, and get the effect of locking to tuner?

73 W9KJO


Re: RD16HHF1 in the uBITX #ubitx

RCBoatGuy
 

The AD8367 is more than twice as expensive as the PE4312, though the AD8367 datasheet does show how to implement AGC with it using 2 additional chips.  So if you want to include AGC with programmable attenuation, the AD8367 may be the way to go.

However, for less than the cost of a single AD8367 you can put two PE3412's in series to get attenuation up to 62dB.  

Not sure what the best trade-off is.  Depends on your needs and price range, I guess.

Carl,
K0MWC

Re: Replacing the Rotary Encoder #ubitx

Walter
 

If locking were accomplished in software then one would have to press the encoder and could shift the frequency.

If the button on the ground wire will work that seems like and nice solution.

73, W9KJO

Re: rv2- messed up setting and txing like mad!!!

Alan -MMØWXT
 

I will rattle through your kindly provided steps once I have a sleep. tiredness and absent mindedness got me into this pickle in the first place.

On that note a VERY BIG THANK YOU. And I will get back to you guys sokn.

73's & NN
Alan

Re: RD16HHF1 in the uBITX #ubitx

Jerry Gaffke
 

The best solution would be to get the transmit power amp chain to behave,
giving uniform power out across the bands.

Failing that, the PE4312 attenuator would be good, though a tough package 
for many to work with.  Almost impossible to just dead-bug into place.

Perhaps we could adjust the value of the emitter resistors at Q90 and Q911/Q912 depending
on the band selected.  Add an extra emitter resistor in parallel, connected to ground only when
a 2n7002 FET is turned on.  Use the band select relaly control lines TXB and TXC to
control the FET's.  Cost of maybe $0.25 in volume.

Jerry, KE7ER


On Tue, Feb 20, 2018 at 12:46 pm, RCBoatGuy wrote:
The AD8367 is more than twice as expensive as the PE4312, though the AD8367 datasheet does show how to implement AGC with it using 2 additional chips.  So if you want to include AGC with programmable attenuation, the AD8367 may be the way to go.

However, for less than the cost of a single AD8367 you can put two PE3412's in series to get attenuation up to 62dB.  

Not sure what the best trade-off is.  Depends on your needs and price range, I guess.

Re: RD16HHF1 in the uBITX #ubitx

Gordon Gibby
 

or maybe just a front panel knob to do "power level"??   Heathkits had one of those..... In this case, it might have to be RF, but if you went with a composite logarithmic, stepped the gain of the TX chain up a bit  (plus apply the final transformer fix)   --- connect  the  "power level" knob with RG-174 coax and set the gain manually for each band if desired.    Just push the key down (or a button if you prefer) and adjust just short of flattopping for example.    


My ICOMs have a "power level" knob.   Of course, it is much the same band to band, but that is a nicety.   


Just having the abilty to GET xx watts of power reliably on any chosen band would be quite nice for such a simple transceiver.   The composite control might not cost THAT much.   A simple fix that even a newbie could wire.   One coax in, one coax out,  mimics the audio volume control.


gordon






From: BITX20@groups.io <BITX20@groups.io> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Tuesday, February 20, 2018 5:00 PM
To: BITX20@groups.io
Subject: Re: [BITX20] RD16HHF1 in the uBITX
 
The best solution would be to get the transmit power amp chain to behave,
giving uniform power out across the bands.

Failing that, the PE4312 attenuator would be good, though a tough package 
for many to work with.  Almost impossible to just dead-bug into place.

Perhaps we could adjust the value of the emitter resistors at Q90 and Q911/Q912 depending
on the band selected.  Add an extra emitter resistor in parallel, connected to ground only when
a 2n7002 FET is turned on.  Use the band select relaly control lines TXB and TXC to
control the FET's.  Cost of maybe $0.25 in volume.

Jerry, KE7ER


On Tue, Feb 20, 2018 at 12:46 pm, RCBoatGuy wrote:
The AD8367 is more than twice as expensive as the PE4312, though the AD8367 datasheet does show how to implement AGC with it using 2 additional chips.  So if you want to include AGC with programmable attenuation, the AD8367 may be the way to go.

However, for less than the cost of a single AD8367 you can put two PE3412's in series to get attenuation up to 62dB.  

Not sure what the best trade-off is.  Depends on your needs and price range, I guess.

Re: Raduino Replacemnt, COMING SOON!

Gerry Kavanagh
 

Fantastic work, Nik. I’d definitely be interested in 2 or 3 smd or th boards, unpopulated. I’m curious to see how the 8307 fares. In my experience they need a fair bit of shielding.
73 de Gerry/EI8DRB 

Re: RD16HHF1 in the uBITX #ubitx

RCBoatGuy
 

You can always buy the board for a little over 17 Euros.

Re: RD16HHF1 in the uBITX #ubitx

Eric KE6US
 

Tough for many to work with because they won't. Homebrewers are going to have to  learn a few SIMPLE and CHEAP tricks to solder devices like this. I've been using this process for several years without difficulties.

A syringe, a small tweezer to place the parts, solder paste and a $20 embossing tool (heat gun) from WalMart or any craft store. It makes the 20-QFN or any other SMT easy. Especially with a PCB or breakout board for the part. Dozens of suppliers make them for every package type. Several of them on OSHPark for dirt cheap and a modest lead time.

http://kd5ssj.com/solderpaste/smt-tools-and-process

I showed my 7 year old granddaughter how to do it, and she begs me to let her do more. The only hard part for her is squeezing the solder paste out of the syringe. She's tiny and doesn't have the hand strength to do it. The paste is thick and the hole in the syringe is very small.

Steady hands and a good magnifying light and you have everything you need. I'm not 7, I'm 75. I wouldn't care if all thru-hole parts disappeared tomorrow, though I might have a problem keeping my boatanchors on the air.

Stop whining about SMT (not you, Jerry) and give it a serious try. It's fun and it's easy. If you make a mistake, heat the part up, scrape it off and start over. No vias to worry about destroying to clean out holes.

Eric KE6US


On 2/20/2018 2:00 PM, Jerry Gaffke via Groups.Io wrote:
The best solution would be to get the transmit power amp chain to behave,
giving uniform power out across the bands.

Failing that, the PE4312 attenuator would be good, though a tough package 
for many to work with.  Almost impossible to just dead-bug into place.

Perhaps we could adjust the value of the emitter resistors at Q90 and Q911/Q912 depending
on the band selected.  Add an extra emitter resistor in parallel, connected to ground only when
a 2n7002 FET is turned on.  Use the band select relaly control lines TXB and TXC to
control the FET's.  Cost of maybe $0.25 in volume.

Jerry, KE7ER


On Tue, Feb 20, 2018 at 12:46 pm, RCBoatGuy wrote:
The AD8367 is more than twice as expensive as the PE4312, though the AD8367 datasheet does show how to implement AGC with it using 2 additional chips.  So if you want to include AGC with programmable attenuation, the AD8367 may be the way to go.

However, for less than the cost of a single AD8367 you can put two PE3412's in series to get attenuation up to 62dB.  

Not sure what the best trade-off is.  Depends on your needs and price range, I guess.

Re: Raduino Replacemnt, COMING SOON!

LKNDAVE
 

#3 sweeper version. this is good
dave
n4lkin

Re: RD16HHF1 in the uBITX #ubitx

Jack, W8TEE
 

I've run into the SMT inertia as well. AT our club meeting next month, I am setting up three solder stations with three of these:


and I'm going to have the members each solder as small a part as they can handle. I think once they do it, they will see how easy it really is. BTW, when done and voltage is applied at the bottom center of the wheel, the LED's should light up. The whole thing cost $2.29 with free shipping! Once they see how easy it is, then I'm going to push how cheap the SMT's are.

Jack, W8TEE



From: Eric KE6US <eric.csuf@...>
To: BITX20@groups.io
Sent: Tuesday, February 20, 2018 9:13 PM
Subject: Re: [BITX20] RD16HHF1 in the uBITX

Tough for many to work with because they won't. Homebrewers are going to have to  learn a few SIMPLE and CHEAP tricks to solder devices like this. I've been using this process for several years without difficulties.
A syringe, a small tweezer to place the parts, solder paste and a $20 embossing tool (heat gun) from WalMart or any craft store. It makes the 20-QFN or any other SMT easy. Especially with a PCB or breakout board for the part. Dozens of suppliers make them for every package type. Several of them on OSHPark for dirt cheap and a modest lead time.
I showed my 7 year old granddaughter how to do it, and she begs me to let her do more. The only hard part for her is squeezing the solder paste out of the syringe. She's tiny and doesn't have the hand strength to do it. The paste is thick and the hole in the syringe is very small.
Steady hands and a good magnifying light and you have everything you need. I'm not 7, I'm 75. I wouldn't care if all thru-hole parts disappeared tomorrow, though I might have a problem keeping my boatanchors on the air.
Stop whining about SMT (not you, Jerry) and give it a serious try. It's fun and it's easy. If you make a mistake, heat the part up, scrape it off and start over. No vias to worry about destroying to clean out holes.
Eric KE6US

On 2/20/2018 2:00 PM, Jerry Gaffke via Groups.Io wrote:
The best solution would be to get the transmit power amp chain to behave,
giving uniform power out across the bands.

Failing that, the PE4312 attenuator would be good, though a tough package 
for many to work with.  Almost impossible to just dead-bug into place.

Perhaps we could adjust the value of the emitter resistors at Q90 and Q911/Q912 depending
on the band selected.  Add an extra emitter resistor in parallel, connected to ground only when
a 2n7002 FET is turned on.  Use the band select relaly control lines TXB and TXC to
control the FET's.  Cost of maybe $0.25 in volume.

Jerry, KE7ER


On Tue, Feb 20, 2018 at 12:46 pm, RCBoatGuy wrote:
The AD8367 is more than twice as expensive as the PE4312, though the AD8367 datasheet does show how to implement AGC with it using 2 additional chips.  So if you want to include AGC with programmable attenuation, the AD8367 may be the way to go.

However, for less than the cost of a single AD8367 you can put two PE3412's in series to get attenuation up to 62dB.  

Not sure what the best trade-off is.  Depends on your needs and price range, I guess.



Re: RD16HHF1 in the uBITX #ubitx

Rob Snow
 

I've caught it too, based on this group.  I ordered several of the above (and couple of the easy ones too) and am going to play and see if I can add "SMT capable" to my meager soldering skills.

Rob
AG5OV