Date   

Re: Crystal CW filter with Version 4 uBITX boards? #ubitx

Bill Cromwell
 

Hi Alex

You can use something like Spectran, fldigi, etc to get an approximation of your receive passband. You will see the noise (and some signals) in the spectral display/waterfall and the noise level will drop off at the left and right ends. That is showing you the passband for the entire system and is largely your IF filter. If you also have audio filters switched in that can have a large influence on the 'noise shadow' you see on your computer screen. Turn off the audio filters to observe your IF filter.

The scale at the bottom of the screen can be set to show you the audio frequencies you are looking at and simple arithmetic then gives the your system bandwidth.

73,

Bill KU8H

On 07/09/2018 09:18 AM, Alex - PA1FOX wrote:
Hi Guys,

Been very busy with other things during the last couple of weeks so I've
not been checking this group also.
Indeed, I got an email from Jim about the crystal filters. And indeed I
use two 10 xtal Cohn ladder filters in parallel, without any switching
hardware. Shifting the IF does from 12 MHz to 4MHz does the trick. I am
very satisfied with the performance, and promised Jim to make some video
recording demonstrating it. My narrow filter is the same setup as the
wide filter, using cheap 4 MHz crystals which were matched with a test
oscillator. The capacitors were set to 68pF but that's a personal
preference. I have not measured it with a spectrum analyzer, but it
'sounds' more narrow than my official INRAD filter in my IC730, which is
400hz.
--snip---
--
bark less - wag more


Re: Tuning knobs with divot

MVS Sarma
 

in my opinion, better that the knob is weaker than the shaft it sits on. Otherwise it would damage the main part itself.  Why not try for a plastic moulded knob?


On Mon, 9 Jul 2018 6:05 PM Arvo KD9HLC via Groups.Io, <arvopl=yahoo.com@groups.io> wrote:
On Sun, Jul 8, 2018 at 05:02 pm, Lee wrote:
Nice knob but they will not sell to the USA.
Same UPC, different seller, looks like they will ship to USA.

https://www.ebay.com/itm/BQLZR-32x13MM-Black-Alloy-Sound-Amplifier-Audio-Volume-Rotary-Control-Knob-/152875802329


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Howard Fidel
 

I would be in favor of adding a frequency on 20 Meters. I have much better luck getting QSOs up there.
Howard

On 7/9/2018 12:28 AM, John Sutter wrote:
Same here down in Silicon Valley.  They were at it until 8:30.  I called a few times after but no luck.
I listened on and off the whole time but didn't hear any call signs either.

I've been having a rough time seeing if the TX side of my BITX40 works well enough to call it functional.
I'm using a Baofeng mic I modified.  On a nearby receiver I sound underwater, but I figure the front-end's
getting compressed pretty badly being so close.

- John
W1JDS



On 7/8/2018 8:04 PM, Mark M wrote:
I listened this afternoon & evening but didn't hear anything here in AZ but noise, good old 40M summer static crashes etc. There are some guys on there now rag chewing at about S9 but I don't know where they are, they haven't identified since I've been listening.

Mark    AA7TA













Re: Crystal CW filter with Version 4 uBITX boards? #ubitx

Alex - PA1FOX
 

Hi Guys,

Been very busy with other things during the last couple of weeks so I've not been checking this group also.
Indeed, I got an email from Jim about the crystal filters.  And indeed I use two 10 xtal Cohn ladder filters in parallel, without any switching hardware. Shifting the IF does from 12 MHz to 4MHz does the trick. I am very satisfied with the performance, and promised Jim to make some video recording demonstrating it. My narrow filter is the same setup as the wide filter, using cheap 4 MHz crystals which were matched with a test oscillator. The capacitors were set to 68pF but that's a personal preference. I have not measured it with a spectrum analyzer, but it 'sounds' more narrow than my official INRAD filter in my IC730, which is 400hz. 

The difficult thing is the software part. You will need four calibration settings for the BFO oscillator. One for wide and narrow USB and one for wide and narrow LSB. This together with a variable sidetone frequency made it a real programming challenge. We don't want the RX frequency to shift when changing from wide to narrow both in USB and in LSB mode. I finally got that working, but my bitx is completely homebrew based on the original ubtix version. I am not using Raduino but a cheap Nano and Adafruit board and my firmware has been considerably modified (but not using the encoder for dial).

Back to the wide/narrow behavior, it's very pleasant to work with. I switch wide/narrow by short pressing the function button and tapping the key at the same time. The video will explain more.

73, Alex
PA1FOX


Re: Removing insulation from fine wires

Jim Lommel <wd8rwi@...>
 

This tool works pretty well.

Jim
WD8RWI

On Fri, Jul 6, 2018 at 12:58 PM, Robert Ogburn <ogburnrobert2@...> wrote:
365 nm...   Here is a picture of the coaxial tool (Harbor Freight)



Re: Tuning knobs with divot

Arvo W0VRA
 

On Sun, Jul 8, 2018 at 05:02 pm, Lee wrote:
Nice knob but they will not sell to the USA.
Same UPC, different seller, looks like they will ship to USA.

https://www.ebay.com/itm/BQLZR-32x13MM-Black-Alloy-Sound-Amplifier-Audio-Volume-Rotary-Control-Knob-/152875802329


Re: Tuning knobs with divot

F5PCX
 

Nick and the group,
I bought two of them last month and they're working fine.
73 - Jean


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

V Zecchinelli
 

Gave it a try at 3PM and 7PM with nothing but noise in NW Vermont.  I could faintly hear talking but unable to make anything out.  No responses to CQ BitX.

73 Vince N1VIN



On 7/5/2018 6:53 AM, John P wrote:
BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Join us as we make contacts with our BitX-40s or uBitXs or anything else on 7.277 MHz in 40 meters!

This is a worldwide event for BitX40 (and other QRP) stations starting at 3PM and 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: D'OH! I figured out my tuner problem...and made my first contact! #ubitx

Warren Allgyer <allgyer@...>
 

The primary function of the 4:1 Unun in the W3EDP EF antenna is as a loss element. To the extent you can tune your end fed directly or through a low loss 1:1 balun, you will put significantly more power into the antenna. 

What is happening is the reflected power from the antenna is 2X attenuated by the balun which fools the ATU into thinking it has achieved match. It is 2X attenuation because the loss of the balun affects and reduces the forward power, reducing your performance, and then reduces the reflected power again, fooling the ATU. High VSWR when using a direct attached antenna has no consequence so long as the rig can deliver its power. Losses through the Unun however are real and do have an effect. Those losses become more significant at lower frequencies such as 160 and on frequencies where the VSWR is higher.

The EF antenna is easy and very effective and can be efficient when used with a tuner alone. When a "balun" is used as a loss element to fool the ATU, it is a lot like a doctor curing a broken leg by putting whiteout on the xrays. It will work but you are losing a minimum of 40% of your power heating up the balun.

Warren Allgyer - WA8TOD


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Vic WA4THR
 

As delivered the BitX40 audio pass band is too low (muffled sounding) in the filter pass band range. A small adjustment will make it sound much better. Google "Improved BitX40 Audio" and see the VK3YE Youtube video about how to fix it.

=Vic=


Re: Removing insulation from fine wires

Peter Möllers
 

I am using different types of wire strippers from Jokari for years, in the business and at home, and I am vetv pleased  with all of them.
https://www.jokari.de/en/

73, Peter
DL5YDA


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

iz oos
 

If you sound underwater it might be the BFO is too close to the bandwidth of the filter. Check whether the opposite sideband is suppressed, if not move the BFO away 300-400hz.


Il 09/lug/2018 06:28, "John Sutter" <jds@...> ha scritto:
Same here down in Silicon Valley.  They were at it until 8:30.  I called a few times after but no luck.
I listened on and off the whole time but didn't hear any call signs either.

I've been having a rough time seeing if the TX side of my BITX40 works well enough to call it functional.
I'm using a Baofeng mic I modified.  On a nearby receiver I sound underwater, but I figure the front-end's
getting compressed pretty badly being so close.

- John
W1JDS



On 7/8/2018 8:04 PM, Mark M wrote:
I listened this afternoon & evening but didn't hear anything here in AZ but noise, good old 40M summer static crashes etc. There are some guys on there now rag chewing at about S9 but I don't know where they are, they haven't identified since I've been listening.

Mark    AA7TA











Re: Tuning knobs with divot

AndyH
 

I have a couple of the Adafruit 'scrubber' knobs.  They're thin and too flexible - they need an almost 'dainty' touch use.  The divot's too shallow to keep a fingertip from sliding off, and the knob's too thin to allow drilling a deeper divot.


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

 

Same here down in Silicon Valley.  They were at it until 8:30.  I called a few times after but no luck.
I listened on and off the whole time but didn't hear any call signs either.

I've been having a rough time seeing if the TX side of my BITX40 works well enough to call it functional.
I'm using a Baofeng mic I modified.  On a nearby receiver I sound underwater, but I figure the front-end's
getting compressed pretty badly being so close.

- John
W1JDS

On 7/8/2018 8:04 PM, Mark M wrote:
I listened this afternoon & evening but didn't hear anything here in AZ but noise, good old 40M summer static crashes etc. There are some guys on there now rag chewing at about S9 but I don't know where they are, they haven't identified since I've been listening.

Mark    AA7TA





Re: D'OH! I figured out my tuner problem...and made my first contact! #ubitx

Alex KA3BQE
 

Been there done that! In fact, I'll be incorporating a new antenna tuner into the shack and expect I'll make the same mistake again...


Re: Tuning knobs with divot

Mark M
 

For you guys who have 3D printers, there are some decent knobs on thingiverse. I printed the one here and I like it. I had to enlarge the hole a tiny bit but it fits & works pretty well. Nice case too if you're looking for one.

https://www.thingiverse.com/thing:2925336

73... Mark AA7TA


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Mark M
 

I listened this afternoon & evening but didn't hear anything here in AZ but noise, good old 40M summer static crashes etc. There are some guys on there now rag chewing at about S9 but I don't know where they are, they haven't identified since I've been listening.

Mark AA7TA


Re: D'OH! I figured out my tuner problem...and made my first contact! #ubitx

VE3MIC
 

Don't be too hard on yourself Gwen, we've all been there before :)
Thanks for sharing.
73 de Mike

On Sunday, July 8, 2018, 9:52:52 p.m. EDT, Gwen Patton <ardrhi@...> wrote:


I built a new antenna yesterday, a 42' version of a W3EDP end-fed. I got a nice 4:1 unun for it, and managed to find some 300-ohm twinlead at Fry's. But I still had the same problem with the Elecraft T1 portable QRP tuner -- it didn't want to tune. I also had a problem with the tuning encoder...I'd try to tune by tiny increments, and suddenly the frequency would start bouncing back and forward, even though I was turning the thing clockwise. I'd just get past say, 7.250, and would try to go to 7.250.050, and it'd jump BACK to 7.249.650. Another click clockwise, and it'd be 7.250.150!

So I tried operating without the ATU last night for a bit, and managed to get to New Hampshire with a 59. I talked to a very nice guy doing the 13 Colonies contest, and he heard me right off the bat. Then I got another contact in New Jersey, but that's awful close to me (I'm in the Phillly 'burbs), so it wasn't a big test. So I got a good, solid contact at a decent distance. It works! But I really want the antenna to be better...so I dug into it today.

I solved both problems today. The ATU problem was a classic PEBCAK -- I reread the documentation, and did some searching on "T1 won't tune", and found the following exhortation over and over: "Check if tuner is in BYPASS MODE..." I checked, and sure enough, it was in the $%^@$^!@$ bypass mode. It wasn't tuning the antenna because it wasn't TRYING to tune. I changed it from bypass to tune mode, and LO! it tuned. (Such an airhead sometimes.)

The frequency tuning issue I solved, along with the fiddly small increment tuning thing, by installing the CEC firmware. I love that I can set the tuning increment. The "turn fast, move fast" feature was okay...but it could be a real pain in the drain. I prefer the constant rate tuning with a selectable increment. It works VERY nicely.

I tried the 7.277 net tonight, but heard nothing. It was 7pm ET, but I didn't get anything. The band was pretty bad right around then, I guess.

I'll keep trying, though. There will be other opportunities.

I have some other antennas to experiment with, two of the Sotabeams end-feds with their own dedicated pico tuners, and the QRPGuys multi-band antenna with the inline traps and dedicated tuner. I'll probably make another of the W3EDP antennas, with better solder joints, and some nice solder lugs on the feedpoint, Kevlar cord at each end, and some new egg insulators I have on order. Then I'll take apart the one I've got in use and rebuild it with the same.

Here's the source of the antenna specs: https://thewakesileave.wordpress.com/2016/08/15/a-42-portable-multiband-hf-antenna-with-no-wire-on-the-ground-the-w3edp-jr/

73,
Gwen NG3P


D'OH! I figured out my tuner problem...and made my first contact! #ubitx

Gwen Patton <ardrhi@...>
 

I built a new antenna yesterday, a 42' version of a W3EDP end-fed. I got a nice 4:1 unun for it, and managed to find some 300-ohm twinlead at Fry's. But I still had the same problem with the Elecraft T1 portable QRP tuner -- it didn't want to tune. I also had a problem with the tuning encoder...I'd try to tune by tiny increments, and suddenly the frequency would start bouncing back and forward, even though I was turning the thing clockwise. I'd just get past say, 7.250, and would try to go to 7.250.050, and it'd jump BACK to 7.249.650. Another click clockwise, and it'd be 7.250.150!

So I tried operating without the ATU last night for a bit, and managed to get to New Hampshire with a 59. I talked to a very nice guy doing the 13 Colonies contest, and he heard me right off the bat. Then I got another contact in New Jersey, but that's awful close to me (I'm in the Phillly 'burbs), so it wasn't a big test. So I got a good, solid contact at a decent distance. It works! But I really want the antenna to be better...so I dug into it today.

I solved both problems today. The ATU problem was a classic PEBCAK -- I reread the documentation, and did some searching on "T1 won't tune", and found the following exhortation over and over: "Check if tuner is in BYPASS MODE..." I checked, and sure enough, it was in the $%^@$^!@$ bypass mode. It wasn't tuning the antenna because it wasn't TRYING to tune. I changed it from bypass to tune mode, and LO! it tuned. (Such an airhead sometimes.)

The frequency tuning issue I solved, along with the fiddly small increment tuning thing, by installing the CEC firmware. I love that I can set the tuning increment. The "turn fast, move fast" feature was okay...but it could be a real pain in the drain. I prefer the constant rate tuning with a selectable increment. It works VERY nicely.

I tried the 7.277 net tonight, but heard nothing. It was 7pm ET, but I didn't get anything. The band was pretty bad right around then, I guess.

I'll keep trying, though. There will be other opportunities.

I have some other antennas to experiment with, two of the Sotabeams end-feds with their own dedicated pico tuners, and the QRPGuys multi-band antenna with the inline traps and dedicated tuner. I'll probably make another of the W3EDP antennas, with better solder joints, and some nice solder lugs on the feedpoint, Kevlar cord at each end, and some new egg insulators I have on order. Then I'll take apart the one I've got in use and rebuild it with the same.

Here's the source of the antenna specs: https://thewakesileave.wordpress.com/2016/08/15/a-42-portable-multiband-hf-antenna-with-no-wire-on-the-ground-the-w3edp-jr/

73,
Gwen NG3P


Re: BITX QSO Afternoon/Evening, Sunday, July 8, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

allen west
 

I also had a nice chat with Randy in Ark.  and Marc in Md.  with stock uBitx and an inverted Vee.


On Jul 8, 2018, at 8:13 PM, Jay - WS4JM <ws4jm@...> wrote:

Nice Chat with Randy in AR, Heard KN4AIE in Chattanooga. Listening on 7.277
Jay WS4JM