Date   
Re: Any Gerber Experts Round Here? #kicad #ubitx

lynatmts@...
 

Hi Ben,

Send me your RS274D files....  lynatmts@...

Lyn WA4GEH

--
"You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."

Re: ATU for mBITX

Peter Parker
 

I would go for a simple manual ATU.  The configuration depending on the antenna being used. 

Some ideas at http://home.alphalink.com.au/~parkerp/projects/projcoupler.htm

73, Peter VK3YE

Re: Personal Best Distance, SSB Phone #ubitx

Peter Parker
 

But otherwise many contacts between VK and USA or Europe with 5w.  Eg

https://www.youtube.com/watch?v=pORkKmdlRWo

 

https://www.youtube.com/watch?v=6U1fmp_CKxE

Re: Personal Best Distance, SSB Phone #ubitx

Peter Parker
 

About 2600km on 80m - with a half-collapsed wire antenna

https://www.youtube.com/watch?v=pZcXBVX-tJk

Re: VK4PP uBitx LPF BANK add-on Board

iz oos
 

I was wondering why the Softrock TXRX had just 3 close bands (mine 10-12-15m). Now I know there were good reasons for that!


Il 31/ago/2018 12:17, "Warren Allgyer" <allgyer@...> ha scritto:

Suggestions based on experience and good practice are all good. It is my experience however that some fairly simple measurements can and need to be made in order to confirm a layout.

First, simply connect up the input and output on a completely unpopulated board and measure the attenuation. If you find less than 80 dB of attenuation at any frequency below 100 MHz, you are probably not going to like the end result. I would then add the relays and check it again. At this point your attenuation needs to be at least 70 dB. Add all remaining components except the filters themselves and check it again. Finally, one at a time, add the filters and check after each one is added.

If, at any step in the process, your input to output crosstalk gets higher than -60 dB, you are not going to be very happy with the outcome. Note all of these measurements are made with the relays deactivated so there is no actual intended path between input and output.

When working on a similar project with Tony Parks for an all-band Softrocks RXTX our first two prototype filter boards measured less than 30 dB isolation between input and output. And we thought we were following good layout and RF principles.

BTW, on the Softrocks project we finally got there........ only to realize that the radio would never make compliance goals without a similarly switched interstage filter prior to the RF drive chain. At that point we had pushed the cost of the radio beyond the target and the project was scrapped.

My bottom line reaction is: layout as best you know how but test, test, test.

WA8TOD


Re: VK4PP uBitx LPF BANK add-on Board

Glenn
 

All good points Warren.   I did some checks of isolation using a typical DIP relay, type HK19F. DPDT

I made a small jig to hold the relays and measure isolation across contacts etc.
Typically it was -34dB across open contacts,
-32dB from one set of contacts to the other. (common terminal)
-41dB from open terminals on each side
-39dB from common of one pole to open on the other pole.
-48db from common to coil.
 At 30MHz.  Better as freq drops of course.
That's without effects of a PCB and various other traces.

glenn

Re: VK4PP uBitx LPF BANK add-on Board

Warren Allgyer <allgyer@...>
 

Suggestions based on experience and good practice are all good. It is my experience however that some fairly simple measurements can and need to be made in order to confirm a layout.

First, simply connect up the input and output on a completely unpopulated board and measure the attenuation. If you find less than 80 dB of attenuation at any frequency below 100 MHz, you are probably not going to like the end result. I would then add the relays and check it again. At this point your attenuation needs to be at least 70 dB. Add all remaining components except the filters themselves and check it again. Finally, one at a time, add the filters and check after each one is added.

If, at any step in the process, your input to output crosstalk gets higher than -60 dB, you are not going to be very happy with the outcome. Note all of these measurements are made with the relays deactivated so there is no actual intended path between input and output.

When working on a similar project with Tony Parks for an all-band Softrocks RXTX our first two prototype filter boards measured less than 30 dB isolation between input and output. And we thought we were following good layout and RF principles.

BTW, on the Softrocks project we finally got there........ only to realize that the radio would never make compliance goals without a similarly switched interstage filter prior to the RF drive chain. At that point we had pushed the cost of the radio beyond the target and the project was scrapped.

My bottom line reaction is: layout as best you know how but test, test, test.

WA8TOD

Re: VK4PP uBitx LPF BANK add-on Board

Timothy Fidler
 

https://www.altronics.com.au/search/all/?sr=Din%2BSocket&pg=16

RE LPF Board 
above as example page.. I can't be  bothered with time of  doing a Cut and paste just to make up a picture of something you know about.. These Green headers must be available all over surely and the plugs to fit em.

If sending signals and power over from main board (using the decoding scheme) you might like to make sure you can
get 12V, zero rail and the three bit signals over on a green horizontal  5.08 pitch header  (this assumes 5V for the decoder generated on the PCB ).. then the user just makes up a cable that picks up all the points on the main board .. direct soldered, Cable  fixed in some way to main PCB and then just plugs into daughter board.   Saves people mixing voltages if they pull the boards apart and then reassemble them as such headers are polarised. .......

Re: Wow... 15 volts in and a bunch out..

VK3HN
 

LT1252 is an transmitter preamp in Wayne Burdick N6KRs Wilderness Simple Solidstate Transceiver, (SST), monoband CW txcvr design, from circa 1999. I built one and added an IRF510 afterburner for 5 watts. Wasn't aware it is in the K2 but Wayne must have liked it.  

Re: VK4PP uBitx LPF BANK add-on Board

Gordon Gibby <ggibby@...>
 

Two suggestions:

1. Looks pretty tight.   You might leave a bit more room for the hobbyist to reassemble the filters

2.  I don’t see RF bypassing on the coil wiring—so signal can bypass the filters on those wires.  Consider caps maybe even series inductors - I used smd 100 micro Henry




On Aug 31, 2018, at 03:29, Timothy Fidler <engstr@...> wrote:

Nick
1. Wired OR diodes used for Relays J1A B  great idea. and I can see you seem to have allowed for relay contacts being opposite sensed. Ie J1A B set is active when Energised and Energised is out of cct.
2 . you have three signals and because of the wired or you have effectively four states without using a decoder. So how is the R5 to be energised. ?? Is it there for case of special software mod plus I2C or ....?

3. You need to define the relay functions.  From a Sota point of view it makes sense that J1AB set is a 20/30m Filter. Ie NO relay energised when working 20m.
then J2 becomes 80 m. then J3 40m  and J4 becomes 15/17 and J5 becomes Ten m after some magic.
4. You have allowed  spike suppression diodes for all relays except first pair. Forgotten or  there is a reason. ? 
5. Kees Talen is also talking of a Five relay board design.  With Decoding to be done Off board somehow. Perhaps you need to check up his thoughts.
6. Given  5.  I would suggest that you allow sufficient pads for a  74HCT42 decoder and  a 78L05 to power it.  These pads could be on basis of wired chip mounted as SM (legs become feet at 2mm up from tips) so the cost of the holes is not there.  You will also need 4 off BS250 P Mosfets  (simplest solution and they are cheap) to activate the last four relays sets.  The points where the Wire goes off to the Wired OR should be  a through hole rondel.  All this could be squeezed in up T LHS of board as presented without much increase in board space.

The final wiring could be done with  Cat E wiring cores stripped out for those who wanted to go this way . I would suggest the following mapping  000 as input to decoder  means nothing.  Same for 001.  010 activates relay set 2 and also energises J1AB via wired OR  .  ...etc all the way to 101. If you use PNP transistors, you will be up for one extra current control resistor per bit.  BS250s are logic level Mosfets  RDS on approx 14R.  Futurlec.com have  them Rockby in Australia list them but have to order them in. 

The mappings and Relay usage have to be defined up front or  the software will be a schmozzle. 

Is the current voltage going to K1 coil 12V .. the schematic calls it Tx voltage. It appears likely to be 12VDC but without details of the guts of the Raduino I cannot be sure.


Re: VK4PP uBitx LPF BANK add-on Board

Timothy Fidler
 

Nick
1. Wired OR diodes used for Relays J1A B  great idea. and I can see you seem to have allowed for relay contacts being opposite sensed. Ie J1A B set is active when Energised and Energised is out of cct.
2 . you have three signals and because of the wired or you have effectively four states without using a decoder. So how is the R5 to be energised. ?? Is it there for case of special software mod plus I2C or ....?

3. You need to define the relay functions.  From a Sota point of view it makes sense that J1AB set is a 20/30m Filter. Ie NO relay energised when working 20m.
then J2 becomes 80 m. then J3 40m  and J4 becomes 15/17 and J5 becomes Ten m after some magic.
4. You have allowed  spike suppression diodes for all relays except first pair. Forgotten or  there is a reason. ? 
5. Kees Talen is also talking of a Five relay board design.  With Decoding to be done Off board somehow. Perhaps you need to check up his thoughts.
6. Given  5.  I would suggest that you allow sufficient pads for a  74HCT42 decoder and  a 78L05 to power it.  These pads could be on basis of wired chip mounted as SM (legs become feet at 2mm up from tips) so the cost of the holes is not there.  You will also need 4 off BS250 P Mosfets  (simplest solution and they are cheap) to activate the last four relays sets.  The points where the Wire goes off to the Wired OR should be  a through hole rondel.  All this could be squeezed in up T LHS of board as presented without much increase in board space.

The final wiring could be done with  Cat E wiring cores stripped out for those who wanted to go this way . I would suggest the following mapping  000 as input to decoder  means nothing.  Same for 001.  010 activates relay set 2 and also energises J1AB via wired OR  .  ...etc all the way to 101. If you use PNP transistors, you will be up for one extra current control resistor per bit.  BS250s are logic level Mosfets  RDS on approx 14R.  Futurlec.com have  them Rockby in Australia list them but have to order them in. 

The mappings and Relay usage have to be defined up front or  the software will be a schmozzle. 

Is the current voltage going to K1 coil 12V .. the schematic calls it Tx voltage. It appears likely to be 12VDC but without details of the guts of the Raduino I cannot be sure.


Re: calibration question #ubitx-help

iz oos
 

Just to exclude you weren't listening the WWV. You also can use the other references at 5 and 15Mhz. Usually when I calibrate something as a double check I use these references too and a shortwave broadcast using ssb


Il 31/ago/2018 00:24, "Mike KK7ER" <groupio@...> ha scritto:
Thanks, Iz Oos!  Just to be sure I'm not missing something subtle, why not just use WWV?  It is AM, isn't it?  And I know for sure that it is on 10.000000 MHz which is more than I can say for AM shortwave broadcasts chosen at random.

--Mike

Re: CW PTT attack time to slow #ubitx

Joop Stakenborg <joop.stakenborg@...>
 

ajparent1/KB1GMX schreef op 2018-08-30 20:55:
Another user installed the KD8CEC software and found it to be an
improvement.
Changing the pull up will not help the issue. The factory code is
slow in
recognizing keying.
Okay!
Yes, I bet it takes a while for the code to recognize if we have a keyer input and then switch from USB to CW... Maybe I should hack the code a bit since I want to stick to the stock firmware for a while.

Another approach I see is changing the hardware input. I will investigate both and get back on this topic.

Allison
Regards,
Joop PG4I

Re: CW PTT attack time to slow #ubitx

Joop Stakenborg <joop.stakenborg@...>
 

Ben Holmes schreef op 2018-08-30 20:17:
This might be a possible fix:
https://qrpguys.com/ubitx-cw-conditioning-adapter
_._,_._,_

Thanks Ben,

will have a look.

Regards,
Joop PG4I

Re: UBITX V3 TX GAIN VARIATIONS

MadRadioModder
 

All of my modelling says it should.  There have been many posts on this subject months ago…  about 400pf is a good start.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Kees T
Sent: Thursday, August 30, 2018 4:57 PM
To: BITX20@groups.io
Subject: Re: [BITX20] UBITX V3 TX GAIN VARIATIONS

 

Allison,

All of the WA2EBY derived dual MOSFET Amp designs I've seen (IRF510, RD16HHF1, RD15HHF1) have a "compensation capacitor" across the output transformer primary.  Used to balance the 3-30MHz range gain. I used one on my 20W Amp kit (and the feedback loop if needed).

The uBITX PA does not have such a capacitor on the schematic .....why ?

73 Kees K5BCQ


Virus-free. www.avg.com

--

…_. _._

Re: VK4PP uBitx LPF BANK add-on Board

Nick VK4PP
 

Probably just the boards, You need to re-use the LPF from the existing board.
Option to add a Firth filter is you want.

Relays are Omron g6s-2 12v

73 Nick VK4PP

Re: VK4PP uBitx LPF BANK add-on Board

ARNAB SEN VU2CMV
 

Dear OM,
               Will you make it available as a kit ? DIY or Assembled ?
73s

ARNAB SEN ( VU2CMV )
6/35 JM SENGUPTA ROAD.
B-ZONE.
DURGAPUR-713205.
MOB:9434833047


On Fri 31 Aug, 2018, 09:10 Nick VK4PP, <nickpullen@...> wrote:
More:

Re: VK4PP uBitx LPF BANK add-on Board

Nick VK4PP
 

More:

Re: UBITX V3 TX GAIN VARIATIONS

MadRadioModder
 

Actually I’ve been doing a lot of experimentation on flattening/ linearizing the transmit chain.  The parts I’ve fallen on are the NE46134’s.  They have plenty of gain, Ft of 5 GHz, and with the proper inter stage transformer design… An almost flat (-0/+0.6 dB) frequency profile swept from 0.5-60 MHz is possible.  I suppose prototyped, it isn’t much of a uBITx though.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Kees T
Sent: Thursday, August 30, 2018 10:46 AM
To: BITX20@groups.io
Subject: Re: [BITX20] UBITX V3 TX GAIN VARIATIONS

 

On Tue, Aug 28, 2018 at 04:25 PM, Rod Davis wrote:

WARNING: q911,q912,q92,q93,q96,q97 all dissipate at least 296 mW. That
means 250 mW transistors are not acceptable.

So, in searching for a better Ft device for the TX chain:
the BFR106 has the dissipation, but the 3.5 to 5GHz Ft invites instability
the MMBT10     lists dissipation at 225 mW, so it may not be a good candidate
the MMBT2369 lists dissipation at 225 mW, so it may not be a good candidate
the DTX2222A has the dissipation, but the Ft is not better than 2n3904, and
the footprint is not compatible with the board.

I was wondering about the reasoning behind using several parallel 2N3904 transistors in the uBITX circuit.....they are inexpensive, but why not just use a single 2N2222 ?

73 Kees K5BCQ


Virus-free. www.avg.com

--

…_. _._

VK4PP uBitx LPF BANK add-on Board

Nick VK4PP
 

Hi All.
Hows this look:


73 Nick VK4PP