Date   
Re: Microphone choices

iz oos
 

If you can't afford a Behemoth microphone (hi hi) you may try high sensitivity (around - 24db) electrec elements you may find at large vendors (Mouser etc). I opted for dynamic elements (not for karaoke) plus a homemade vogad compressor.


Il 10/apr/2019 13:22, "David - CA3DPV" <david.parra@...> ha scritto:
My two cents...

First I've tried with a karaoke mic and a audio console 
Good: I get 10W of power without effort, talking quietly
Bad: The signal transmitted is extremely low pitch (very dificult to copy). 

Now I use a PC mic (purchased for a few bucks). PTT is a button installed on it.
Good thing: It's a very cheap and small desk microphone (3 USD), 
Bad thing: It's a low gain mic, get 4 or 5 watt only @40m

Re: Microphone choices

David - CA3DPV
 

My two cents...

First I've tried with a karaoke mic and a audio console 
Good: I get 10W of power without effort, talking quietly
Bad: The signal transmitted is extremely low pitch (very dificult to copy). 

Now I use a PC mic (purchased for a few bucks). PTT is a button installed on it.
Good thing: It's a very cheap and small desk microphone (3 USD), 
Bad thing: It's a low gain mic, get 4 or 5 watt only @40m

Re: Poor mans spurs and harmonics check with uBitxandcommercial radio

Joe Puma
 

Yes the uBitx might have some flaws but not hard to find issues with other radios or how a ham is using it, mods, running power, etc. There are a lot of aging radios out there, my 840 is of the latest breed and I was told when I bought it a year+ ago that the owner had recently purchased and  went SK shortly after.  I reviewed the alignment procedure quite a bit but I don’t have the right test equipment to run through the procedures and I’ve been firm on not using the radio a guinea pig, that’s what the uBitx is for.

 

 

Joe

 

 

Sent from Mail for Windows 10

 

From: iz oos
Sent: Wednesday, April 10, 2019 2:51 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Poor mans spurs and harmonics check with uBitxandcommercial radio

 

:) I think the TX of the ubitx has been the most tested, loved and blamed by hams in history. Also because it should be assumed that commercial ones should have no basic issue in terms of harmonics and spurs. However mods in commercial rigs are not that infrequent and the consequences of these should also be thoroughly tested. And of course some might always say, yeah the 840 is an old radio that needs to be 'aligned', you would better off buying a new rig!

 

Il 10/apr/2019 08:01, "Joe Puma" <kd2nfc@...> ha scritto:

Looks like the ubitx screenshot didn’t get attached properly, here they both are again for comparison.

 

 

 

 

 

 

Sent from Mail for Windows 10

 

From: Joe Puma via Groups.Io
Sent: Wednesday, April 10, 2019 1:51 AM
To: BITX20@groups.io
Subject: [BITX20] Poor mans spurs and harmonics check with uBitx andcommercial radio

 

Hi,

 

I just did a quick comparison test between my ubitx and Yaesu ft-840 radio.  I used a SDR on a laptop with a up converter, the SV1AFN with a 200mhz LO. I had a multiband antenna on it from a Yaesu XV-7R, its tuned to receive AM broadcast band. I was using Touchstone and scanning from 200-230mhz (0-30mhz). The ubitx was transmitting around 12watts,  the FT-840 at 10watts but with CW key down and they were both transmitting on antenna EFHW antenna.

 

The ubitx show two spikes that the FT-840 does not show  at all but its almost similar with other spurs. The signal appears stronger with the FT-840 but its spurs are relatively similar to ubitx. Actually the ubitx spurs seem to be relatively less from main signal when compared to FT-840.

 

I have to find a local ham club with some gear to test the uBitx and maybe the FT-840 while I’m at it. 😊

 

 

 

 

 

 

 

 

This is a no TX baseline.

 

 

 

 

Joe

KD2NFC

 

Sent from Mail for Windows 10

 

 

 

Re: uBitx V5 Audio improvement

Jim Tibbits
 

Attached couple of mods I've been using ...One variable audio filter and one mod Re 386 ...
The 386 shows what I measured on the ic with a 10 uF cap pin 1-8 ...flat from near dc to daylight ..What I heard was LOTS of wideband noise ..Cut it with the installed L/C filter ... then installed the op-amp variable filter ..found I did not need the 386 bandpass mod with the variable filter ...both mounted on same board and plugged into U1 socket on V3 board ...dono what would be needed to adapt to ver 4/5

Jim
LM386 Bandpass Filter.jpeg


On Tue, Apr 9, 2019 at 9:26 PM Ashhar Farhan <farhanbox@...> wrote:
Exact!

On Tue 9 Apr, 2019, 12:09 PM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
For LM386 gain that is flat across 300 to 2300 Hz 
and is more than 26dB (no cap) but less than 46dB (10uF cap),
this is done by adding a resistor in series with that 10uF cap.

Re: Poor mans spurs and harmonics check with uBitx andcommercial radio

iz oos
 

:) I think the TX of the ubitx has been the most tested, loved and blamed by hams in history. Also because it should be assumed that commercial ones should have no basic issue in terms of harmonics and spurs. However mods in commercial rigs are not that infrequent and the consequences of these should also be thoroughly tested. And of course some might always say, yeah the 840 is an old radio that needs to be 'aligned', you would better off buying a new rig!


Il 10/apr/2019 08:01, "Joe Puma" <kd2nfc@...> ha scritto:

Looks like the ubitx screenshot didn’t get attached properly, here they both are again for comparison.

 

 

 

 

 

 

Sent from Mail for Windows 10

 

From: Joe Puma via Groups.Io
Sent: Wednesday, April 10, 2019 1:51 AM
To: BITX20@groups.io
Subject: [BITX20] Poor mans spurs and harmonics check with uBitx andcommercial radio

 

Hi,

 

I just did a quick comparison test between my ubitx and Yaesu ft-840 radio.  I used a SDR on a laptop with a up converter, the SV1AFN with a 200mhz LO. I had a multiband antenna on it from a Yaesu XV-7R, its tuned to receive AM broadcast band. I was using Touchstone and scanning from 200-230mhz (0-30mhz). The ubitx was transmitting around 12watts,  the FT-840 at 10watts but with CW key down and they were both transmitting on antenna EFHW antenna.

 

The ubitx show two spikes that the FT-840 does not show  at all but its almost similar with other spurs. The signal appears stronger with the FT-840 but its spurs are relatively similar to ubitx. Actually the ubitx spurs seem to be relatively less from main signal when compared to FT-840.

 

I have to find a local ham club with some gear to test the uBitx and maybe the FT-840 while I’m at it. 😊

 

 

 

 

 

 

 

 

This is a no TX baseline.

 

 

 

 

Joe

KD2NFC

 

Sent from Mail for Windows 10

 

 

Re: Poor mans spurs and harmonics check with uBitx andcommercial radio

Joe Puma
 

Looks like the ubitx screenshot didn’t get attached properly, here they both are again for comparison.

 

 

 

 

 

 

Sent from Mail for Windows 10

 

From: Joe Puma via Groups.Io
Sent: Wednesday, April 10, 2019 1:51 AM
To: BITX20@groups.io
Subject: [BITX20] Poor mans spurs and harmonics check with uBitx andcommercial radio

 

Hi,

 

I just did a quick comparison test between my ubitx and Yaesu ft-840 radio.  I used a SDR on a laptop with a up converter, the SV1AFN with a 200mhz LO. I had a multiband antenna on it from a Yaesu XV-7R, its tuned to receive AM broadcast band. I was using Touchstone and scanning from 200-230mhz (0-30mhz). The ubitx was transmitting around 12watts,  the FT-840 at 10watts but with CW key down and they were both transmitting on antenna EFHW antenna.

 

The ubitx show two spikes that the FT-840 does not show  at all but its almost similar with other spurs. The signal appears stronger with the FT-840 but its spurs are relatively similar to ubitx. Actually the ubitx spurs seem to be relatively less from main signal when compared to FT-840.

 

I have to find a local ham club with some gear to test the uBitx and maybe the FT-840 while I’m at it. 😊

 

 

 

 

 

 

 

 

This is a no TX baseline.

 

 

 

 

Joe

KD2NFC

 

Sent from Mail for Windows 10

 

 

Poor mans spurs and harmonics check with uBitx and commercial radio

Joe Puma
 

Hi,

 

I just did a quick comparison test between my ubitx and Yaesu ft-840 radio.  I used a SDR on a laptop with a up converter, the SV1AFN with a 200mhz LO. I had a multiband antenna on it from a Yaesu XV-7R, its tuned to receive AM broadcast band. I was using Touchstone and scanning from 200-230mhz (0-30mhz). The ubitx was transmitting around 12watts,  the FT-840 at 10watts but with CW key down and they were both transmitting on antenna EFHW antenna.

 

The ubitx show two spikes that the FT-840 does not show  at all but its almost similar with other spurs. The signal appears stronger with the FT-840 but its spurs are relatively similar to ubitx. Actually the ubitx spurs seem to be relatively less from main signal when compared to FT-840.

 

I have to find a local ham club with some gear to test the uBitx and maybe the FT-840 while I’m at it. 😊

 

 

 

 

 

 

 

 

This is a no TX baseline.

 

 

 

 

Joe

KD2NFC

 

Sent from Mail for Windows 10

 

Re: uBitx V5 Audio improvement

Ashhar Farhan
 

Exact!


On Tue 9 Apr, 2019, 12:09 PM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
For LM386 gain that is flat across 300 to 2300 Hz 
and is more than 26dB (no cap) but less than 46dB (10uF cap),
this is done by adding a resistor in series with that 10uF cap.

Re: Microphone choices

Kelly Mabry
 

Hi Mike,  a lot of ideas abound; some are repurposed cb microphones,  some are home brewed with what's in the kit, I ordered a Uniden BC645 4-Pin Microphone for CB Radios, electret mic, going to wire the 4 pin panel plug to fit the microphone.  Others have changed out the 4 pin to match their 8 pin QRO rigs. I would dig around the ubitx.net site and hfsignals.com ... Somewhere I  remember that a dynamic mic needs a tantalum cap on the input. But in reality there are even 3d printed mic housings to assemble a mic. Check out https://shop.kit-projects. They have mics and paddles!
73,
Kelly K5AID 

Microphone choices

Michael Goins, k5wmg <wmgoins@...>
 

Looking to use my BITX on SSB and cw and trying to figure out a good mike for it, either hand or desk. Will likely take to Costa Rica later in the year and possibly leave there. Suggestions or where to look for more information?

Re: CW key sticking with Nextion LCD

Joe Puma
 

Which bitx are you using. I have uBitx and R52 is near audio predriver and its a 2n3904. How do I do this on a uBitx v3. I guess this is what we call a carrier burst?

 

Joe

KD2NFC

 



On Apr 9, 2019, at 12:34 PM, Sam Tedesco <stedesco619@...> wrote:

 

Hi Joe,

There was a blocking diode fix on r52 that fixed all of my cw issues. I'm going off of memory...but, I lifted r52, on side towards 2822 chip, add diode in series...cathode down to board. I run my delay 450-500

 

Re: v5 12m/10m Spectrums

Curt
 

Ron

thanks I found them.  see if your instrument under units can be changed from dB v to dB m.  I think that may change the result. 

Curt

Re: Trial to control CW power (and reduce harmonics as a result) by unbalancing the 2nd mixer #ubitx

John (vk2eta)
 

Thank you all for your replies. Much appreciated.

I will do more work based on your input and report back on the results.

73, John (VK2ETA)

Re: Trial to control CW power (and reduce harmonics as a result) by unbalancing the 2nd mixer #ubitx

Jerry Gaffke
 

Maybe.
Except it is working just fine at the first mixer on thousands of uBitx's.


On Tue, Apr 9, 2019 at 02:07 PM, Dexter N Muir wrote:
It seems the slightest leakage from "open" unbalances the mixer -and an Arduino output doesn't deliver that cleanly. Physically switching the key, direct from the panel socket or by relay, may be the only way to get clean CW by this method.
73, Dex ZL2DEX

Re: Trial to control CW power (and reduce harmonics as a result) by unbalancing the 2nd mixer #ubitx

Dexter N Muir
 

It seems the slightest leakage from "open" unbalances the mixer -and an Arduino output doesn't deliver that cleanly. Physically switching the key, direct from the panel socket or by relay, may be the only way to get clean CW by this method.
73, Dex ZL2DEX

Re: v5 12m/10m Spectrums

ronmhauser@...
 

Ok, zipped in files section, deleted from photos section

Re: v5 12m/10m Spectrums

ronmhauser@...
 

Gah!  I guess the website shrinks the file resolution, they are not readable.  Hm.  Maybe there is a way to upload the full resolution pics

v5 12m/10m Spectrums

ronmhauser@...
 

Hi everyone.  Someone, I think Curt, asked about spectrum results on 12m/10m which I had not looked at previously.  The screen caps are in Photos (not files) under my call, K0EIA.  If I am reading this right, 12m looks ok, 10m not quite.  I haven't done a build nor an analysis like this before, so let me know what you see.

My setup is an Analog Discovery 2 puck generating 20mV - 50mV pp at 1kHz on the terminals of the mic connector, and a clip lead to ground the PTT.  The AD2 also takes the spectrum off a 47dB tap on my dummy load, and I have a diamond antenna crossed needle swr meter that reads 0-20w.  I experimented with varying the microphone level from 50mW to 30-20mW, and varying RV1.  Max in the filename is RV1 turned maximum counterclockwise.

73
--Ron
K0EIA

Re: CW key sticking with Nextion LCD

Sam Tedesco
 

Hi Joe,

There was a blocking diode fix on r52 that fixed all of my cw issues. I'm going off of memory...but, I lifted r52, on side towards 2822 chip, add diode in series...cathode down to board. I run my delay 450-500

Re: Trial to control CW power (and reduce harmonics as a result) by unbalancing the 2nd mixer #ubitx

Jerry Gaffke
 

John,

Topology is different between first and second mixers on the uBitx.
I'd do your mod as proposed, but cut traces to T4 pins 3,5 and 6.
Swap them so T4 pins 3,5 are in from R47, pin 6 is out to C211.

Not yet obvious to me why it would matter.
But Farhan likely made that first mixer at T2 different than all 
other mixers on the uBitx and Bitx40 for a reason. 

Jerry, KE7ER