Date   
Re: No TX #ubitx

joe kallo <quietglow@...>
 

Okay I fiddled with all the torroids with the key down and saw no evidence of shorts. Also no activity on the power meter. I tested tx in 80, 40 and 20m with the same results on all. I heard signals on 80&40 (it's too early for 20 here still). I didn't check solder continuity on the torroids as that will mean taking it apart. I'll do that next.

Also of note: I had the key down for 30-45 second periods while messing around and the finals transistors did not change temperature to the touch.

Re: Si5351/A Utility Console

Ken KM4NFQ <km4nfq@...>
 

Wow. Thanks. I just got a couple of Si5351As from http://www.qrp-labs.com/synth.html so I'm looking forward to trying your console, hopefully sometime in the near future. 73 Ken, KM4NFQ

On Mon, Jan 1, 2018 at 9:32 PM, Bruce MacKinnon KC1FSZ <bruce@...> wrote:
This has been very useful to me so I'll share it in case it is useful to others.

I have written an Arduino sketch that provides a simple command-line console (serial) to control most features of an Si5351/A.  This provides a very generic tool that can be used during the early phases of home-brew rig development when you just want to get the RF/IF chain up and running in a minimal way without fooling around with displays, encoders, Arduino coding, etc.  Just load up this sketch, connect the I2C pins to the Si5351/A, open he Serial Monitor (or other terminal program) and you're ready to start tuning.

There are some handy features that make it easy to deal with superhet math and filter pass-band tweaking. The details are here: https://github.com/brucemack/Si5351-Console.

I'm doing a scratch-build of the BITX-40 with some modifications so I've been using this sketch a lot.  For my BITX I use CLK0 for the VFO, CLK2 for the BFO, and CLK1 as an RF signal injector/tester.  Here is a video of the receive side up and running: https://www.youtube.com/watch?v=nueR5nY3wYc

Happy New Year and 73s,

Bruce KC1FSZ 


Re: BITX20 Ver3C SBL VFO

Mvs Sarma <mvs_sarma@...>
 

Congrats and best of 2018.

You could perhaps tailor the range by chaging the top and bottom resistors of the 10T potentiometer.
Reduce bottom resistor for further downing on lower side or increase to increase low end.

like wise, upper resistor increase causes lowwers the high end freq . and viceversa.

cheers
 sarma
 vu3zmv

On Tuesday 2 January 2018, 2:07:38 PM IST, Kevin Luxford <kbgluxford@...> wrote:


Building Sunil's kit. VFO completed. Lo freq = 3.957 MHz. Hi freq = 4.477 MHz. Range is a bit wider than I would like.  Will look at ways of restricting the range.  However the FLL makes it absolutely rock steady.  LED extinguishes in less than a second. Wound L4 with a slightly heavier guage wire that solders through the coating.  Had to wind the last few turns back over the earlier ones.  This will probably add a bit of capacitance in parallel to the inductance, but it seems to work OK.  Using RG316 which I have on hand instead of the RG174 supplied because longer interconnections seemed advantageous when testing and fiddling about. On to the next stage!

Re: Tell me your favorite uBitx mods

KD8CGH
 

The present keying system doesn't work reliably. I have had problems with it and others have also reported problems. A fix has been suggested that uses the same analog multi level scheme, but I think a digital key interface would be more reliable. I see that you have included something in your schematic.

By narrower filter I meant an adjustable audio filter. I'm adding a Sotabeam dual bandwidth CW filter to mine with a 3 position switch. Position one is out (original SSB filter), two is Sotabeam wide and three is Sotabeam narrow. A handy feature is that the filter can activate an led when you are well tuned and I'm adding that. The filter is placed in line with the volume control. I'm also adding the PTT audio mute pop fix from the Wiki that grounds the same line from volume control. Both are on a piece of perf board attached by two of the nuts that hold the speaker.

An alternative audio filter could be a SCAF that goes on the audio output.

For digital modes an isolation transformer and either a VOX or CAT control for PTT.

Thanks for starting a Christmas list.

Re: No TX #ubitx

Reid Campbell
 

I got caught out by leaving the brown PA supply wire off while I got the
Rx working. Have you checked that?

Cheers

Reid Gi8TME/Mi0BOT

Okay I fiddled with all the torroids with the key down and saw no evidence
of shorts. Also no activity on the power meter. I tested tx in 80, 40 and
20m with the same results on all. I heard signals on 80&40 (it's too early
for 20 here still). I didn't check solder continuity on the torroids as
that will mean taking it apart. I'll do that next.

Also of note: I had the key down for 30-45 second periods while messing
around and the finals transistors did not change temperature to the touch.

Re: No TX #ubitx

 

Joe,

If you have a radio to monitor in the shack, put a short 6" wire to C80 and see if you can hear yourself on a receiver.

If OK try the next stage C84.

Check all the DC voltages in the TX stages with PTT pressed and mic disconnected.

Raj

At 02-01-2018, you wrote:
Okay I fiddled with all the torroids with the key down and saw no evidence of shorts. Also no activity on the power meter. I tested tx in 80, 40 and 20m with the same results on all. I heard signals on 80&40 (it's too early for 20 here still). I didn't check solder continuity on the torroids as that will mean taking it apart. I'll do that next.

Also of note: I had the key down for 30-45 second periods while messing around and the finals transistors did not change temperature to the touch.

BCI filter question.

KG5NII
 

I am thinking seriously about experimenting with the uBitX but am wondering in advance if someone could suggest  a good broadcast band filter I can build that is known to be effective. I live less than 1 mile (1.6 km) from a 50 kW AM broadcast station transmitting on 1180 kHz. I know this will be a problem with on the uBitX as even on mid, high end commercial ham rigs I get significant interference on 3540, 7040, 14160 kHz and so on.   In fact, I'd probably want to build an additional one for my Yaesu.  I know there are a lot of circuits out there for BCI filters but that doesn't necessarily mean they are or would be effective.  Cost is a major concern,  and commercial filter units seem to be rather pricey, but on the other hand, purchasing the components, etc may not necessarily be cost effective either given the somewhat high cost of shipping and given that  not everything could necessarily be purchased from one place, thereby rising costs even more.    I'd probably want to build one for the uBitX and one for my 100W Yaesu  just to give it over and done with.  There is not a day that goes by that I do not wish the four AM 1180 transmitter  towers down the road from me  are flattened by a tornado until I realize that would only be a temporary reprieve at best  but building, installing some good filters will be a permanent one.  


So advice please.


Thanks.

Ron, KG5NII



Re: No TX #ubitx

joe kallo <quietglow@...>
 

By PA supply wire, do you mean the wire to the speaker/headphone jack? If so, yes that's hooked up. It's working as a receiver (i.e. I'm copying activity on the bands) playing through a pair of headphones.

Re: No TX #ubitx

Gordon Gibby <ggibby@...>
 

​no, he means the 2nd  connection for power to the power amplifier.


On the bitx40 it is a separate 2-conductor plug/pins


on the ubitx it is an additional wire on the 3-wire power connector....


if you don't have power going to the pwer amplifier....won't have any output


IN TX, the heatsink should go to +12 V DC.  you can check the tab of the irf510 with  voltmeter




gordon



From: BITX20@groups.io <BITX20@groups.io> on behalf of joe kallo <quietglow@...>
Sent: Tuesday, January 2, 2018 8:56 AM
To: BITX20@groups.io
Subject: Re: [BITX20] No TX #ubitx
 
By PA supply wire, do you mean the wire to the speaker/headphone jack? If so, yes that's hooked up. It's working as a receiver (i.e. I'm copying activity on the bands) playing through a pair of headphones.

Re: No TX #ubitx

Reid Campbell
 

No, there are 3 wires to the power plug, I think they are Black (0v), Red
(12v Rx power) and Brown (12v/24V PA power). The Brown and Red wires
should both be connected to the 12V power via the on/off switch on the
volume control.

The two supply wires allow you to feed a different (higher) voltage to the
PA transistors to achieve higher output power.

It just sounds like there is no power being applied to the PA stage.

By PA supply wire, do you mean the wire to the speaker/headphone jack? If
so, yes that's hooked up. It's working as a receiver (i.e. I'm copying
activity on the bands) playing through a pair of headphones.

Re: BCI filter question.

Gordon Gibby <ggibby@...>
 

so....that sounds like even with harmonic suppression, you have SIGNIFICANT energy coming at your on the harmonics of their primary frequency.....


hopefullly it ISNT being created within some nonlinear junction in your own radio....the way to prevent that would be a high pass filter in your transmission line designed to pass anything above, say 2 MHz and not pass stuff below that.    I'm guessing you already have those kinds of filters?


beyond that, the actual hamonic radiated energy generated by THEIR TRANSMITTER  is a fact of life, and you aren't going to be able to receive much (other than them) on those frequencies....


if you try and builld a notch filter (high Q, narrow bandwidth) for each of their harmonics youll hear them less....but you'll also hear other people near those frequencies less also....





From: BITX20@groups.io <BITX20@groups.io> on behalf of KG5NII <kg5nii@...>
Sent: Tuesday, January 2, 2018 8:52 AM
To: BITX20@groups.io
Subject: [BITX20] BCI filter question.
 

I am thinking seriously about experimenting with the uBitX but am wondering in advance if someone could suggest  a good broadcast band filter I can build that is known to be effective. I live less than 1 mile (1.6 km) from a 50 kW AM broadcast station transmitting on 1180 kHz. I know this will be a problem with on the uBitX as even on mid, high end commercial ham rigs I get significant interference on 3540, 7040, 14160 kHz and so on.   In fact, I'd probably want to build an additional one for my Yaesu.  I know there are a lot of circuits out there for BCI filters but that doesn't necessarily mean they are or would be effective.  Cost is a major concern,  and commercial filter units seem to be rather pricey, but on the other hand, purchasing the components, etc may not necessarily be cost effective either given the somewhat high cost of shipping and given that  not everything could necessarily be purchased from one place, thereby rising costs even more.    I'd probably want to build one for the uBitX and one for my 100W Yaesu  just to give it over and done with.  There is not a day that goes by that I do not wish the four AM 1180 transmitter  towers down the road from me  are flattened by a tornado until I realize that would only be a temporary reprieve at best  but building, installing some good filters will be a permanent one.  


So advice please.


Thanks.

Ron, KG5NII



Re: No TX #ubitx

 

Joe had earlier mentioned as far I remember that he had done the TX
current bit. So we have to look elsewhere!

Raj

At 02-01-2018, you wrote:
No, there are 3 wires to the power plug, I think they are Black (0v), Red
(12v Rx power) and Brown (12v/24V PA power). The Brown and Red wires
should both be connected to the 12V power via the on/off switch on the
volume control.

The two supply wires allow you to feed a different (higher) voltage to the
PA transistors to achieve higher output power.

It just sounds like there is no power being applied to the PA stage.

By PA supply wire, do you mean the wire to the speaker/headphone jack? If
so, yes that's hooked up. It's working as a receiver (i.e. I'm copying
activity on the bands) playing through a pair of headphones.

Re: Tell me your favorite uBitx mods

jamesrocks4ever@...
 

Maybe an Si570 for low phase noise. Serial connection for possible remote operation with the rtl and web sdr on a tablet. I have been thinking about laying out modules in 0805 two sided boards to make it fit in a smaller package. 
 I was actually waiting to get the ubitx until the first wave of mods. I’ve had the bitx out of a case more than in one doing mods.

James

Sent from my iPhone

On Dec 31, 2017, at 20:29, Diver Martin <diver.martin@...> wrote:

Hello all,

As I'm doing a motherboard mod, I'm looking to incorporate a bunch of mods into one PCB.  Right now, what I've got going are the following:

* A tuner + SWR Bridge (phase detector maybe?)
* A spot for an RTL-SDR (blogV3) dongle
* AGC Modifications
* Integrating LCD and headphone/mic/BNC/Power/etc jacks into the PCB

Other things I've thought about, space depending:

*Adding in footprints for a chinese AD9850 DDS module for one of the clock signals

I would like to hear the top mods you've done, and what you'd love to see integrated into a motherboard PCB that fits on top of the uBitx.  Battery charger?  Battery adapter? I dunno, bring it on!  If you have a favorite AGC mod, please tell me about it, and make some suggestions as well.  This is not promising to be a cheap kit, and full of SMT, but something I might make available.

Happy new year,

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

Re: BCI filter question.

Karl Heinz Kremer, K5KHK
 

For a cheap BCI filter, take a look here (it's the first article in this document): http://www.qrpforum.de/index.php?page=Attachment&attachmentID=16959&h=269da5721a0d272fc6ce550399700bfc9d9a8155

For a simpler, but slightly more expensive solution, see here: http://www.qrpme.com/?p=product&id=BCI

If you want something you can leave in during transmit, take a look here: http://vk3il.net/projects/broadcast-band-filter/

You an also calculate your own, all you need is a high-pass filter that cuts off just above the AM band. As Gordon suggested, a notch filter might be a good idea as well. 
--
Karl Heinz - K5KHK

Re: Wiring encoder

Jack, W8TEE
 

All:

Before messing around with the unsoldering/resoldering the connections, if you have the Arduino IDE installed and are comfortable with it, load the ubitx_20.ino source code file and locate line 75-76:

#define ENC_A (A0)
#define ENC_B (A1)

Try reversing these symbolic constants:

#define ENC_B (A0)
#define ENC_A (A1)
and see if that restores the proper rotation. Mine is all bundled up for a pending presentation, and I don't want to unpack it.

Jack, W8TEE


From: ekelley <ekelley828@...>
To: BITX20@groups.io
Sent: Tuesday, January 2, 2018 1:07 AM
Subject: [BITX20] Wiring encoder

A word of caution when wiring the encoder. The schematic on page one
has the encoder wiring reversed. Don't wire it up by the schematic
use the picture, you will see that the red and yellow wires are reversed
and the black and brown are reversed. I made the mistake of wiring everything
up using the schematic. When tuning my frequency goes down with clockwise
rotation of encoder. Goes up with counter-clockwise rotation.
Ed



Virus-free. www.avast.com

Re: BITX20 Ver3C SBL VFO

Kevin Luxford
 

Thanks for your help, Sarma. Will try that tomorrow. This VFO is the most stable that I have ever worked with. Can't wait to get it on the air. 73 all, Kevin VK3DAP / ZL2DAP


--
Kevin B. G. Luxford
kbgluxford@...

Re: Si5351/A Utility Console

Arv Evans
 

Bruce

Thanks for sharing.  I am working on a piece of test equipment that uses Si5351a and
found your command interpreter interesting and informative. 

Arv  K7HKL
_._


On Mon, Jan 1, 2018 at 7:32 PM, Bruce MacKinnon KC1FSZ <bruce@...> wrote:
This has been very useful to me so I'll share it in case it is useful to others.

I have written an Arduino sketch that provides a simple command-line console (serial) to control most features of an Si5351/A.  This provides a very generic tool that can be used during the early phases of home-brew rig development when you just want to get the RF/IF chain up and running in a minimal way without fooling around with displays, encoders, Arduino coding, etc.  Just load up this sketch, connect the I2C pins to the Si5351/A, open he Serial Monitor (or other terminal program) and you're ready to start tuning.

There are some handy features that make it easy to deal with superhet math and filter pass-band tweaking. The details are here: https://github.com/brucemack/Si5351-Console.

I'm doing a scratch-build of the BITX-40 with some modifications so I've been using this sketch a lot.  For my BITX I use CLK0 for the VFO, CLK2 for the BFO, and CLK1 as an RF signal injector/tester.  Here is a video of the receive side up and running: https://www.youtube.com/watch?v=nueR5nY3wYc

Happy New Year and 73s,

Bruce KC1FSZ 


Re: Tell me your favorite uBitx mods

John Pieper
 

i addressed the erratic keying a few days ago but it sank like a stone.
The reluctance to send the first dit is due to the firmware. It is trying to enforce correct character spacing but the consequence is that the paddle is sampled very slowly when it is open (i.e. a character is not already started). I was able to undo this in my setup and always sample as fast as possible (within constraints of not using interrupts, which people seem to have a problem with) and got much better responsiveness. See message 37720 for details.

John AD0RW

Re: No TX #ubitx

joe kallo <quietglow@...>
 

Actually, I was going to post this as a separate issue, but in the PA bias step my initial reading was outside the range mentioned in the directions. With both bias pots at fully clockwise, I measured 420 mA when PTT is depressed. The directions indicate it should be 470 - 500. Could this be the problem?

Fwiw, my power supply is a 30A 12v deal.

Again, many thanks for the help!

Joe

Re: Tell me your favorite uBitx mods

 

Dave : 

For CW filtering on my BITX40 I used a SOTABEAMs Laserbeam DSP Audio Filter module and it works brilliantly. 

If you are a hard-core contester then it is no substitute for a real narrow IF filter but then again, if you are a hard-core
contester you are likely using a radio that costs more than $129. For casual CW use, a very good AF filter does wonders. 

These little DSP modules come pre-assembled, are simple to wire up and outperform any analog audio filter I have ever used. 
There are a number of options for the Dual Filter and there is a also one with a variable filter bandwidth as well. 
If you install the optional signal LED, it doubles as a CW tuning indicator (i.e. it blinks in time with the signal when 
it is in the middle of the filter passband). Also the current draw is around 30ma. 

Best of all they start at around $US30 and shipping costs from the UK are very reasonable. 

I picked up a second module that I plan to use on my uBITX. 

Cheers 

Michael VE3WMB 

P.S. Here is a link : 

https://www.sotabeams.co.uk/audio-products/

P.P.S. Usual disclaimer applies .. I have no financial interest in SOTABEAMs ... I am just a very satisfied customer.