Date   
Re: FDIM/Dayton hamvention, room to share

Jay Davis
 

 I stay at the red roof inn across the intersection by the gas station.  I had stayed at the holiday inn but they wouldn't let my bengal stay there.  Maybe more of us are going and we could have a ubitx meet and greet . Would be nice to see some ubitxs in person and their owners.  I've been a Dayton attendee for 20+++ years.  Most that I know from dayton remember my bengal cat every year.  He's my best salesman and has lots of repeat customers for him. 
  Jay N3QPW

Newest addition to the shack!

Nelson
 

I got my uBITx wired up today and powered it up this afternoon.  Not much on the air but I did go out to my jeep and fired up my Yaesu FT-817ND on 10 meter and had my wife listen down in the shack.  She said it hurt her ears it was so loud (I had the AF Gain up all the way) but other than that it worked fine.

Now I just need to get the microphone wired up and/or a key wired up so I can test the transmitter portion.  For the key I think I will just make an adapter from the 1/4" mono plug I use on my other rigs.  The mic I will use is a mic that I use with my Baofeng UV-5.  I will modify the plugs to be separate plugs for the mic and external speaker.  I just need to get a couple of the appropriate size jacks.  Dang I wish Radio Shack still had a store in town.  As it is, I will need to mail order the plugs for the mic external speaker and key.  In the mean time I will spend some time surfing the bands and listening on it :-)

Attached is a picture of it in the shack.
Nelson
KG7GYS 

Re: RD16HHF1 power curve flattening...some

John <passionfruit88@...>
 

Henning and Glen,

Thanks you for the feedback. All interesting questions.

I sincerely hope someone with the test equipment can duplicate and fill in the blanks.

The only test I can think of performing is the 1dB compression point. Since I would use an RF probe with a diode I need a high enough input voltage to make the test meaningful even after correction for the diode's threshold.

So if the gain compression is most likely to be in the final can I measure the output of the driver's stage and the output of the finals while I sweep the RV1 pot for an analysis of the 1dB compression? Also should I measure before or after the LPFs?

All the best,

73, John (VK2ETA)

Re: My uBitx with 5v mod #ubitx

Joe Puma
 

Cool idea. I have a 5v regulator. I’m wondering if I can use it for a 5 volt supply in the radio and if there would be benifits to supplying tne Raduino too. But I was sure if my would create switching noise. I’ve tried to use it on my Mic (md- 100) for power source and got nothing but noise. But that might of not been the regulators fault.  

This is what I have below. 

Re: Erratic tuning with my new uBitx

Mike Woods
 

Chris

Selecting the extended menu is not well documented for either stock or KD8CEC versions of the firmware.  You select the "settings" menu, and wait for it to return to the frequency display (exiting the menu system). Now press the button again and you should see the extended menu settings.

In relation to the tuning step.  The step values offered are completely customisable (I have 1Hz, 10Hz, 100Hz and 1kHz as options), but need to be configured using the PC software "uBITx Manager" developed by Ian.  Go to his website (www.hamskey.com) and find the post about "uBITx Manager".  It is a very useful tool to install.  There are Windows and Linux versions.

73 Mike ZL1AXG

On 22/03/18 2:33 AM, Chris Clarke wrote:
I also have a little bit of a problem getting the Extended Menu after selecting "Setup On?". Sometimes I get the Extended Menu, mostly I don't. I haven't discovered a surefire way of getting the Extended Menu, just seems a matter of luck. Fortunately it's not something I need to return to often.

Also it seems the maximum tuning step is 200Hz. This is not a very useful value - 1MHz would be much more useful to me.  I'm looking at the code to see if and how I could change the values for "tuneStepIndex". Are you able to you advise on this?
--
Mike Woods
mhwoods@...

Re: RD16HHF1 power curve flattening...some

Glenn
 

 Henning, I too am skeptical about power out above about 16W with RD16HHF1's..

In my setup here, i see flattening of the output waveform around the 14-15W mark, measured  with no LPF on the output. I amusing the G6ALU output topology. I am not yet feeding the supply to the finals via the Balun core method but intend to try that asap.

glenn


On Wed, Mar 21, 2018 at 05:18 am, Henning Weddig wrote:

even with the mods. the TX string shows a 3 dB drop in output power...

Please exchange the two single chokes L8 / L9 with a bifilar wound coil on a e.g. FT43-50 core, see the reasons for that mod in the description already cited in this forum  "ludens.cl".

BTW: how was the output power determined?

How does the power curve PIn - POut look like,

Is the output power measured at the 1 dB compresion point?

Tests on my tries to build a PA with the RD16HFF1´s using different output transformer configurations (even with a 1:4 guanella transformer with 25 ohm coaxial cable on two BN43-202 cores + Balun with 50 ohm coaxial cable on a FT43-80 torroid core + bifilar choke (FT43-50 torroid) + extra choke on the center tap  with a R-C combinaiton to terminate even harmonics) I was not able to get more than 10 W output power at P1dB.  Therefore I am really sceptical about the high power results of > 16 W.

The "hot" cores show that something must be wrong!

Did You measure the suppression of the even harmonics which should be well suppressed  (at least 40 dB) ? How good are the odd harmoncis suppressed?  If the third harmonic is only 10 dB down (1/3 of the amplitude of the fundamental wave) the PA produces square waves, which is not a performance of a linear amp.

IM performance??

Henning Weddig
DK5LV

Am 21.03.2018 um 12:41 schrieb John:
Hello Nik,

How did you go with the feedback issue?

My power amp mods in summary:  finals as RD16HHF1s, feedback resistors R261/R262 as 820 Ohms, Transformer 2T primary / 3T secondary on BN43-202, 180pF across the output transformer primary and 330pf across R87/R88. That's all...in a way.

Heavily inspired by Erhard's (DF3FY) information as displayed on uBitx.net.

Results per band at 14V supply, RV1 at %60, RD16's biased at 250mA each:
Band      output power   Total current
80M        22W                         2.9A
40M        20W                         3.2A
30M        16W                         2.3A
20M         16W                        2.7A
17M         15W                        2.4A
15M         12W                        1.6A
12M         12W                    not measured
10M         12W                        1.7A

At 22W the output transformer does get warm but not the LPFs.

Wound back RV1 to get 9-10W on the high frequency bands and 16-18W on the lower ones.

All the best,

73, John (VK2ETA)

 On Wed, Mar 21, 2018 at 05:18 am, Henning Weddig wrote:

even with the mods. the TX string shows a 3 dB drop in output power...

Please exchange the two single chokes L8 / L9 with a bifilar wound coil on a e.g. FT43-50 core, see the reasons for that mod in the description already cited in this forum  "ludens.cl".

BTW: how was the output power determined?

How does the power curve PIn - POut look like,

Is the output power measured at the 1 dB compresion point?

Tests on my tries to build a PA with the RD16HFF1´s using different output transformer configurations (even with a 1:4 guanella transformer with 25 ohm coaxial cable on two BN43-202 cores + Balun with 50 ohm coaxial cable on a FT43-80 torroid core + bifilar choke (FT43-50 torroid) + extra choke on the center tap  with a R-C combinaiton to terminate even harmonics) I was not able to get more than 10 W output power at P1dB.  Therefore I am really sceptical about the high power results of > 16 W.

The "hot" cores show that something must be wrong!

Did You measure the suppression of the even harmonics which should be well suppressed  (at least 40 dB) ? How good are the odd harmoncis suppressed?  If the third harmonic is only 10 dB down (1/3 of the amplitude of the fundamental wave) the PA produces square waves, which is not a performance of a linear amp.

IM performance??

Henning Weddig
DK5LV

Am 21.03.2018 um 12:41 schrieb John:
Hello Nik,

How did you go with the feedback issue?

My power amp mods in summary:  finals as RD16HHF1s, feedback resistors R261/R262 as 820 Ohms, Transformer 2T primary / 3T secondary on BN43-202, 180pF across the output transformer primary and 330pf across R87/R88. That's all...in a way.

Heavily inspired by Erhard's (DF3FY) information as displayed on uBitx.net.

Results per band at 14V supply, RV1 at %60, RD16's biased at 250mA each:
Band      output power   Total current
80M        22W                         2.9A
40M        20W                         3.2A
30M        16W                         2.3A
20M         16W                        2.7A
17M         15W                        2.4A
15M         12W                        1.6A
12M         12W                    not measured
10M         12W                        1.7A

At 22W the output transformer does get warm but not the LPFs.

Wound back RV1 to get 9-10W on the high frequency bands and 16-18W on the lower ones.

All the best,

73, John (VK2ETA)

Re: FT8 on my uBITX #ubitx

Randy
 

That is the one I bought.

Re: FT8 on my uBITX #ubitx

M Garza <mgarza896@...>
 

On Wed, Mar 21, 2018 at 4:09 PM, Richard Spohn <wb2gxm@...> wrote:
To KC5SB -- Bill, this is a great case!  Where did you buy it?  -- Rich WB2GXM




Re: FT8 on my uBITX #ubitx

Richard Spohn
 

To KC5SB -- Bill, this is a great case! Where did you buy it? -- Rich WB2GXM

Re: ESP8266 or ESP32 Raduino Alternatives?

bobolink
 

Great Michael. TFT displays might present a challenge. Don’t know.

Here is my goofing around with ADC/DAC real-time audio. 
github
Not required for bitx.
DAC is only 8 bits (48 dB dynamic range), ADC interrupt is on a timer so some conversion clock skew.
Continue to be amazed with ESP32.

bob
wm6h

Re: My uBitx with 5v mod #ubitx

Nigel G4ZAL
 

Here it is happily decoding FT8 on 40M via a cheap USB sound card/dongle.
Next step is the CAT control via the USB on the rear panel (connected to the Raduino) using KD8CEC firmware.

Re: FT8 on my uBITX #ubitx

Tim Gorman
 

I *wanted* the voltage drop. I could only adjust my power supply down
to 13v. Using the diode in series dropped the voltage to about 12.4v.
Helps protect the main board from damage.

tim ab0wr

On Wed, 21 Mar 2018 12:54:43 -0700
"w7hd.rh" <w7hd.rh@...> wrote:

That is a silicon diode with a 0.6v-1.0v drop.   A better choice
would be a Schottky diode, such as this one from Amazon


20 pcs for $6.99 isn't bad!  With only a 0.2v drop, it's very
unobtrusive and handles up to 15a of current.

Ron W7HD

On 03/21/2018 11:55 AM, Randy wrote:

Found an 1N5404 in an old UPS and will measure the voltage drop.

Randy

Re: FT8 on my uBITX #ubitx

w7hd.rh <w7hd.rh@...>
 

That is a silicon diode with a 0.6v-1.0v drop.   A better choice would be a Schottky diode, such as this one from Amazon


20 pcs for $6.99 isn't bad!  With only a 0.2v drop, it's very unobtrusive and handles up to 15a of current.

Ron W7HD

On 03/21/2018 11:55 AM, Randy wrote:

Found an 1N5404 in an old UPS and will measure the voltage drop.

Randy

-- 
Ron W7HD - NAQCC#7587 OMISS#9898 KX3#6966 LinuxUser#415320
Editor OVARC newsletter

My uBitx with 5v mod #ubitx

Nigel G4ZAL
 

I have finished my build and modded it a little in readiness for adding additional boards/hacks.
I cut the track feeding the TDA2822 and fed it with 5v from a little Radio Control UBEC.
At the same time, I removed the 5v reg on the Raduino and fed that from the UBEC as well.
You can see from the pics, I added a little 'bus'. for picking off further 5v supplies as required.


Re: Any gotchas replacing the TDA2822 with an LM386? #ubitx #ubitx-help

John McClun
 

A drop in replacement - YES.  Look at the data sheets, exactly the same.

--
John
NQ3RP

Re: FT8 on my uBITX #ubitx

Randy
 

Found an 1N5404 in an old UPS and will measure the voltage drop.

Randy

Re: how to reset the calibration

Skip Davis
 

Tim, I did the same thing and a reload of the firmware corrected the problem.

Skip Davis, NC9O

On Mar 21, 2018, at 14:22, Tim Gorman <tgorman2@...> wrote:

In playing around with the menu's on the ubitx I seem to have somehow
gotten the LSB calibration so far out of whack I can't hear anything.

With the dial set to 3.925Mhz I hear nothing. Moving the signal
generator to 3.938Mhz indicates a signal being received but no tone.

Do I just need to reload the firmware to start over? Or is there an
easier way to reset to default values?

tim ab0wr


how to reset the calibration

Tim Gorman
 

In playing around with the menu's on the ubitx I seem to have somehow
gotten the LSB calibration so far out of whack I can't hear anything.

With the dial set to 3.925Mhz I hear nothing. Moving the signal
generator to 3.938Mhz indicates a signal being received but no tone.

Do I just need to reload the firmware to start over? Or is there an
easier way to reset to default values?

tim ab0wr

Re: Microphone, simple fix.

Dennis Voorhees
 

That looks like what i may have. This RS one has 3 wires. Mine does too. I connected it with the minus wire to ground and one terminal. The "hot" to the other terminal. What I have works nicely now. 


On Wed, Mar 21, 2018 at 10:34 AM, John McClun <john@...> wrote:
Denny -

There may not be any stores left but RS is still in the e-com business.  Try this element:
https://www.radioshack.com/products/electret-microphone-element-with-leads

--
John
NQ3RP


Re: FT8 on my uBITX #ubitx

Tim Gorman
 

The diode is a 10amp rectifier diode I had in the junk box. Probably
overkill.

tim ab0wr

On Wed, 21 Mar 2018 02:23:29 -0400
"Joe Puma" <kd2nfc@...> wrote:

Yea that diode is pretty chunky. Please share

Joe