Date   
Re: BITX QSO Afternoon/Evening, Sunday, April 15, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

John P
 

Note that the Georgia QSO party will be in progress until 8PM EDT on Sunday, so the band might be a little crowded!
--
John - WA2FZW

ubitx encoder hookup breadboard.

_Dave_ K0MBT
 

I was disappointed to see the light duty encoder that came with ubitx. 
I couldn't see the connection points as being solid enough to offer reliability. 

My solution was to attach the encoder to a fiberglass perf board and solder the leads to the board. 
Like this:
http://veloliner.com/ham/encoderboard.JPG

how to reach Farhan about a new radio board

Richard E Neese
 

I have had request from some local hams to see if a 2meter qrp 5/10 w ssb board could be designed based on farhans design ?
with and without digital vfo option?

Re: uBITX shipping time

Will, AI4VE
 

I placed my order on Mar 8 and received shipping notice today. I'm using India Post so probably won't see the product for another three weeks or so. I'm excited!

Re: TDA2822 fried

Bill KC5SB
 

I have toasted 2 of them so far.  I installed a socket after the first one died and bought several more for spares.  So far no problems after the second one was installed - crossed fingers.  Hope I don't jinx myself on Friday the 13th.

Re: uBITX shipping time

 

Ordered my uBitx  on 17 March and got shipping notification today 4/13, that it has been shipped via DHL..
Looks like the shipping department has built up a "head of steam" :-)

73's

Jeff WA1WXL

Re: BITX QSO Afternoon/Evening, Sunday, April 15, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

tony.vasile@...
 

Hi John,

I am new to the group, and new to BITX.  I have a freshly assembled BITX40, and am excited to try and make some contacts on Sunday with other BITX fans! 

I just wanted to know if the Sunday BITX QSO event is weekly, or is it scheduled ad hoc?

Thanks and 73!

Tony, KB9A

On Fri, Apr 13, 2018, 7:17 AM John P <j.m.price@...> wrote:
BITX QSO Afternoon/Evening, Sunday, April 15, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!

This is a worldwide event for BITX40 stations starting at 7pm in each time zone. To participate, call CQ BITX on Sunday, starting at 3PM and/or 7PM your local time. The BITX QSO Night continues through the evening and conditions usually improve after sunset, so it is worthwhile to participate later in the evening.

Suggested Best Operating Practices:

Work at QRP power levels unless conditions require more power.
Call and listen for CQ BITX on the hour and every quarter hour.
It is helpful if you call CQ BITX with your callsign, name and location. 
Repeat your callsign a number of times during your CQ BITX and during QSO's.
Start a QSO by confirming the callsign, location, name and signal report of the other operator.
Say the callsign, name and location of the other operator so others can hear.
If the frequency is busy, avoid long conversations.
After your initial QSO is complete, ask if there are any other stations who would like to contact.

Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.

This is an undirected, scheduled event.  The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls on Sunday evening.  Talk to you then!
--
John - WA2FZW

Re: uBITX shipping time

 

They must have shipped a massive batch ... mine is in Cincinnati already ...
--
check http://n9god.com for electronics publication in English and Foreign formats

Re: ubitx encoder hookup breadboard.

Arv Evans
 

Davesters

Almost all the inexpensive encoders are of that style and manufacture.  A more
robust unit could be provided but that would significantly increase cost of the
transceiver.  Once those small encoders are mounted to a panel they are quite
stable and reliable. 

There are many rotary encoders available from on-line dealers.  Most are similar
to that provided by HFSignals, and some cost much more and are physically
larger.  Some of the smaller ones have per-step detents, some have per-two-step
detents, and some have no mechanical detents.  There are also variations in the
number of detents per rotation.  If you change to a different style of encoder you
may need to modify the software to account for dual-step detents and for more or
less detents per rotation. 
There is also an earlier scheme that was used on some transceivers where a
potentiometer was used for variable rate up/down tuning.  In those systems the
amount the knob was turned from center position caused the frequency to be
adjusted up or down in step sizes that were related to the offset from center
position. 

Arv  K7HKL
_._


On Fri, Apr 13, 2018 at 8:14 AM, <davesters@...> wrote:
I was disappointed to see the light duty encoder that came with ubitx. 
I couldn't see the connection points as being solid enough to offer reliability. 

My solution was to attach the encoder to a fiberglass perf board and solder the leads to the board. 
Like this:
http://veloliner.com/ham/encoderboard.JPG


Pressing 14 pin LCDs into I2C service #parts

Kevin Luxford
 

I had in my bowerbird boxes some LCD displays purchased some years ago.  Thinking that if an I2C controller backback were to be attached, they would make handy displays for BITX or any other project.  Only 4 wires to write and control is very attractive. So some I2C backback controllers arrived from China via eBay, and it was intended to attach the controller to the LCD display like the prototype unit that was already working.  On unwrapping the LCDs from their bubble wrap, I discovered, quelle horreur, that the LDCs had only 14 pins.  Well 16 into 14 does not go, so to the LCD a 14 pin female header was soldered, the controller plugged into the female header leaving pins 15 and 16 dangling in the breeze.  Upon firing up the test program in the Nano and rotating the contrast pot on the controller, the contents of the text eventually appeared.  However, no backlight on the LCD meaning that it had to be operated in reasonably high ambient light.  Looking at the pinout diagram, a possible hack was perceived. At the right hand end of the LCD were two unused contacts, marked A and K.  Connecting A to Pin 2 (Vcc) and K to Pin 1 (GND) resulted in a backlight appearing.
Here are a couple of pix showing the hack.  The first picture shows the two wires added to bring power to the backlight, while the second shows the female header and the dangling Pins 15 and 16. 73 Kevin VK3DAP / ZL2DAP

Re: uBitX: Ordered Feb 20, received ship notice today, Apr. 6 #ubitx

yachtdesign@...
 

arrived today 13.34h local time, so only 2 days shipping India-Germany. Impressive!
Customs clearance with 33 Euro tax, which is ok in my point of view.
73
DJ6MZ

uBITX SSB filter response question #ubitx

Michael LeBlanc
 

Friends:

I'm scratch-building a uBITX, and completely new to building crystal filters. Attached is the response curve of the 12MHz SSB filter using my PHSNA. 
Does this look like it will work satisfactorily in the radio? To select the crystals, I used the K8IQY crystal test fixture and chose the closest ones to 12MHz from a bag of 50 inexpensive computer crystals.

I don't know if my PHSNA is accurately calibrated, so although it looks like the filter passes between 11997 and 12000, I'm not sure how much error there is in the frequency readings. But I'm pretty sure that the -20dBm passband is less than 2.5khz. If the passband is slightly to one side of 12MHz, does that matter?

I've received a new bag of 100 crystals, and I'm wondering if I should take the time to characterize all of them and replace the 8 that are currently on the board with ones that have a closer match. Any thoughts?

-Michael VE1LEB

Re: uBITX SSB filter response question #ubitx

Rod Davis
 

Hi Michael,

In the ubitx, the crystal filter is driven/terminated in a 200 ohm impedance.

It is likely your PHSNA is 50 ohms.

The passband ripple you are seeing can be severely influenced by driving/terminating impedances.

Are you measuring the filter with the transformers at each end, or are you going direct to the
crystal connections?

It is normal for the passband to be below 12 MHz. On my ubitx, the BFO is at 11,997,117 Hz, so
that will give you a sense of how far below 12 MHz the passband is.

Only experimentation and measurement will answer your question about characterizing the
batch of 100.

When I built a Minima from scratch, I used a batch of 100 crystals. When I saw the part-to-part
variation, I was glad I measured all 100. I wrote serial numbers on them, put the frequencies
in a spread sheet, and sorted them by frequency to get the best match.

You are probably eager to get on the air; however,

I suggest the journey is as important as the destination.


Good luck with all,

Rod KM6SN


On 04/13/2018 08:22 AM, Michael LeBlanc wrote:
Friends:

I'm scratch-building a uBITX, and completely new to building crystal filters. Attached is the response curve of the 12MHz SSB filter using my PHSNA. 
Does this look like it will work satisfactorily in the radio? To select the crystals, I used the K8IQY crystal test fixture and chose the closest ones to 12MHz from a bag of 50 inexpensive computer crystals.

I don't know if my PHSNA is accurately calibrated, so although it looks like the filter passes between 11997 and 12000, I'm not sure how much error there is in the frequency readings. But I'm pretty sure that the -20dBm passband is less than 2.5khz. If the passband is slightly to one side of 12MHz, does that matter?

I've received a new bag of 100 crystals, and I'm wondering if I should take the time to characterize all of them and replace the 8 that are currently on the board with ones that have a closer match. Any thoughts?

-Michael VE1LEB


Re: uBITX SSB filter response question #ubitx

Rod Davis
 

Michael,

Not sure where I saw it, either here or on emrfd email group: the quality of the capacitors
used in a crystal filter are quite important. Using NPO or C0G is highly recommended.

Other ceramics have a piezo-electric feature that is not desirable.

Also, grounding the crystal cases is of paramount importance.

Rod KM6SN



On 04/13/2018 08:22 AM, Michael LeBlanc wrote:
Friends:

I'm scratch-building a uBITX, and completely new to building crystal filters. Attached is the response curve of the 12MHz SSB filter using my PHSNA. 
Does this look like it will work satisfactorily in the radio? To select the crystals, I used the K8IQY crystal test fixture and chose the closest ones to 12MHz from a bag of 50 inexpensive computer crystals.

I don't know if my PHSNA is accurately calibrated, so although it looks like the filter passes between 11997 and 12000, I'm not sure how much error there is in the frequency readings. But I'm pretty sure that the -20dBm passband is less than 2.5khz. If the passband is slightly to one side of 12MHz, does that matter?

I've received a new bag of 100 crystals, and I'm wondering if I should take the time to characterize all of them and replace the 8 that are currently on the board with ones that have a closer match. Any thoughts?

-Michael VE1LEB


Re: uBITX SSB filter response question #ubitx

Michael LeBlanc
 

Thanks Rod. I'm enjoying the journey and for the time being I can get on the air any time with my appliance radio. ;-)

I was measuring it 'naked', without the transformers. Just before reading your reply, though, I measured it again but through the transformers, and the result is "softer":

I also was fastidious about recording the individual crystal measurements, and (like you), put them in a spreadsheet and asked it to re-order the crystals by centre frequency. Thanks also for your thoughts on the filter's centre frequency. As long as I'm in the ballpark, I'm happy.

-Michael VE1LEB

Re: Ian Lee KD8CEC integration of SDR demo #ubitx

James Lynes
 

If you are a Linux user, take a look at Gqrx(gqrx.dk). It's based on gnu radio and has a distribution for the Raspberry Pi.

Gqrx has a TCP/IP remote control interface and command API. I have written several wrappers in Perl and wxPerl to implement additional functionality such as scanning.

James

Re: uBITX SSB filter response question #ubitx

Satish Chandorkar
 

In both the curves without and with transformer your filters loss appears to be around -7 db's
In my opinion this is bit too high -3db is just right up to -5db is acceptable according to the
experts, what type of capacitors are used in this filter? The multi layer ceramic capacitors
are really of lo loss. If you use the modern SMD ones in my opinion that will reduce the loss
in the filter   

Virus-free. www.avast.com

On Fri, Apr 13, 2018 at 9:35 PM, Michael LeBlanc <michaelleblanc1@...> wrote:
Thanks Rod. I'm enjoying the journey and for the time being I can get on the air any time with my appliance radio. ;-)

I was measuring it 'naked', without the transformers. Just before reading your reply, though, I measured it again but through the transformers, and the result is "softer":

I also was fastidious about recording the individual crystal measurements, and (like you), put them in a spreadsheet and asked it to re-order the crystals by centre frequency. Thanks also for your thoughts on the filter's centre frequency. As long as I'm in the ballpark, I'm happy.

-Michael VE1LEB


Re: BITX QSO Afternoon/Evening, Sunday, April 15, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

John P
 

We do it every week! Welcome to the club! 
--
John - WA2FZW

Re: TDA2822 fried

Joe Puma
 

Bill which chips were you using? 


On Apr 13, 2018, at 10:37 AM, Bill KC5SB <blmerideth@...> wrote:

I have toasted 2 of them so far.  I installed a socket after the first one died and bought several more for spares.  So far no problems after the second one was installed - crossed fingers.  Hope I don't jinx myself on Friday the 13th.

Re: uBITX SSB filter response question #ubitx

ajparent1 <kb1gmx@...>
 

One warning when measuring narrow filter use a very slow sweep.  At narrow resolutions if
the sweep is too fast the curve will not match the actual.  It is as much detector response
time as its filter delays.  When too fast the it will appear tilted, and when you slow down
you will see more accurate result.

The filter insertion loss in the 4 to 7 db  range sounds correct.  Though I might be better if
higher Q capacitors are used we are not talking a 3DB difference.  Also dId you calibrate
out the transformers first?  That can add a DB of loss sometimes more.

Allison

Allison