Date   
Re: BITX QSO Afternoon/Evening, Sunday, June 17, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Howard Fidel
 

I just heard Tom, VE3THR marine 4, he heard me but didn't copy and then disappeared. Called CQ a few times, didn't hear anyone else.

Howard - WB2VXW

On 6/17/2018 7:45 PM, WS4JM wrote:
Heard Tom and another station earlier, most likely John, but couldn't get back to either, still trying!

WS4JM


Anyone ever use one of these to build a Raduino clone?

Dennis Yancey <bigbluedry@...>
 

Has anyone used one of these to build a Raduino clone?  If so, any issues I need to be aware of either hardware Sr software related?

https://www.digikey.com/catalog/en/partgroup/si5351a-clock-generator-breakout-board/55065?utm_adgroup=Programmers%20Dev&slid=&gclid=EAIaIQobChMI7dPJs_Pb2wIVDJFpCh3uVQ_jEAAYASAAEgKikvD_BwE

Re: BITX QSO Afternoon/Evening, Sunday, June 17, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Jay - WS4JM
 

Heard Tom and another station earlier, most likely John, but couldn't get back to either, still trying!

WS4JM

Re: BITX QSO Afternoon/Evening, Sunday, June 17, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

John P
 

I heard Tom (VE3THR) for a moment or two, but the noise level is AWFUL!
--
John - WA2FZW

Re: Remote cooling fan indicator #ubitx

Joe
 

This quite common. To eliminate the problem make sure you have a hash filter.
Typically a 1000mfd capacitor or higher with a small resistor ( 2-10 ohm) in series, followed by another similar capacitor .. Basically a pi filter with a series resistor in the middle.

 I use them on my rigs to kill noise, especially fan noise.

Joe
VE1BWV


On Sun, Jun 17, 2018, 5:41 PM Rob Snow <rsnow@...> wrote:
I installed my 12v auxiliary cooling fan in my uBITX earlier today to replace the unseemly box fan I had propped up over my open cased radio.  After I installed it and dialed in the temps I fired up WSJT-X to see if there was any performance changes with the fan on, well, lo and behold I discovered that I have a "remote digital fan on indicator" on all bands so I'm assuming it's getting in via the audio circuit not RF side.  It also turns off when the fan does.  Perfect, I think I'll leave it.

Behold:

Re: Help with AGC kit wiring

Don, ND6T
 

You got it! I do recommend the 3 position SPDT on-off-on switch idea, though, for the front panel control. Otherwise, Kees included those shorting plugs for you. You're Welcome! 73, Don

Re: Raduino needed.

Nick VK4PP
 

I have a spare stock Raduino. Email me....

73 Nick VK4PLN

Re: BITX QSO Afternoon/Evening, Sunday, June 17, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

John P
 

I'm calling CQ on 7277 but have a S9 noise level here, so not sure I'll hear anything!
--
John - WA2FZW

Re: Help with AGC kit wiring

Bill Carpenter
 

Just so I got this, the 3 pin connector replaces the coax connections so the only other connections are the +5 Volts and the twisted pair from the volume control?  Looks like a very elegant solution!  I like being able to mount the board securely.

Thanks!

Re: No S-Meter nor callsign showing in KD8CEC #ubitx

Ralph Mowery
 

Did you run the ubitx Memory  Manager program with the new software loaded ?  If so,did you go to the s-meter part of the program and turn  the s-meter on and enter some numbers in the  blocks ? It works fine for me using the original 16x02 display.

On Sun, Jun 17, 2018 at 5:23 PM, Sascha Bohnet via Groups.Io <saschabohnet@...> wrote:
Hello everybody,

I just installed ND6Ts AGC Circuit and wanted to turn on the S-Meter in the firmware according to the instructions on
KD8CECs Homepage.
However I just can't get it on the display.

Whatever I selection of options I choose,  the only things i get on my standard 16x02 Parallel Display is

VFO A, VFO B, Mode, and tuning steps. I can change which VFO is shown first (toggling) or switch on (and off) rotation,
but I am not able to get my callsign or the S-Meter on the display.

The S-Meter signal is there - i checked it in the setup, ADC Pin7 gets read and a reasonable value is shown.

Am i doing something wrong? I thought first I may have accidently uploaded the 16x04 P Firmeware and reuploaded again -
this was not the case.

However according to the pictures (http://www.hamskey.com/2018/05/setting-smeter-to-ubitx-with-cec.html) there must be a way.

Any help would be appreciated.

Sascha, DL5SMB
_.
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Re: No S-Meter nor callsign showing in KD8CEC #ubitx

Philip
 

UBITX_CEC_Vxxxxx_16P.hex  : It is the LCD equipped with uBITX. Default LCD, 16x02 Parallel LCD This is the one you need

Sorry I cant help anymore as it works fine for me.

Re: No S-Meter nor callsign showing in KD8CEC #ubitx

Sascha Bohnet | DL5SMB
 

I did this of course.
I checked the box in the Ubit Manager on the PC, pressed encode and reuploadet it. Turned the radio off and on again. No change :-/

Re: RF AGC experiments #ubitx

Don, ND6T
 

Thanks for sharing Mike. I found that most of my 2N7002's had about 10 pF output capacitance, the specs show up to 30 pF. Still not bad compared. I found that I got about 23 dB maximum attenuation with the shunt connection. Did you make a quantitive measurement? Hard to tell much from the audio clip but it sounded much like my first circuit (simple shunt). Makes for an easy mod, though! My next step was just to hang another 2N7002 across the output of first IF which added another 15 dB or so. The series element made the big difference, though. 73, Don

Re: An Apology and clarification #ubitx

Dr Fred Hambrecht
 

He needs to remember to put a tener in the mailbox on boxing day. On another note I received 3 Bitx and 1 uBitx with nary a scratch.

 

v/r

Fred W4JLE

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Brian L. Davis
Sent: Sunday, June 17, 2018 14:55
To: BITX20@groups.io
Subject: Re: [BITX20] An Apology and clarification #ubitx

 

So sorry that your postal system is so destructive, maybe you should contact them instead of this group!
Being a retired Electronic service engineer and college lecturer I suggest that instead of maligning the creators of these radios that do work, you design a radio that will do what these radios do and sell it for $120.  If you can't or won't then please stop whining, it's unbecoming of anyone with an Amateur Radio license, with or without your background!

Re: RF AGC experiments #ubitx

Mike
 

Just to elaborate a bit: if you look at the datasheets for the different FETs above you can see that the output capacitance varies a lot from large size fets to small size fets. If the output capacitance is too high, you loose control over the AGC shunting effect / series resistance effect since ther will be lower isolation due to the capacitance.

Re: No S-Meter nor callsign showing in KD8CEC #ubitx

Philip
 

You need to run Ubitx Manager on your PC.

Philip G7JUR

No S-Meter nor callsign showing in KD8CEC #ubitx

Sascha Bohnet | DL5SMB
 

Hello everybody,

I just installed ND6Ts AGC Circuit and wanted to turn on the S-Meter in the firmware according to the instructions on
KD8CECs Homepage.
However I just can't get it on the display.

Whatever I selection of options I choose,  the only things i get on my standard 16x02 Parallel Display is

VFO A, VFO B, Mode, and tuning steps. I can change which VFO is shown first (toggling) or switch on (and off) rotation,
but I am not able to get my callsign or the S-Meter on the display.

The S-Meter signal is there - i checked it in the setup, ADC Pin7 gets read and a reasonable value is shown.

Am i doing something wrong? I thought first I may have accidently uploaded the 16x04 P Firmeware and reuploaded again -
this was not the case.

However according to the pictures (http://www.hamskey.com/2018/05/setting-smeter-to-ubitx-with-cec.html) there must be a way.

Any help would be appreciated.

Sascha, DL5SMB

uBitx V4 linearity mod in final audio amplifier #ubitx

Mike
 

I believe there is an nonlinearity problem on some of the newer V4 uBitx radios (the one with transistors in the final audio amp). Two of my radios had this problem.
The problem is that the two diodes in the final amp doesn't make a voltage drop that is larger than the drop over the BJT B-C junction drops, so there will be a crossover distortion problem.

I did a mod: cut the trace between the diodes. Soldere in a 500 ohm pot paralelled with the a 125 ohm resistor. I adjusted the pot from a low value and increased the resistance until the nonlinearity disappeared by listening to a moderately strong cw signal. I checked the lower transistor so it didnt become too warn from the quiescent current.

73s

RF AGC experiments #ubitx

Mike
 

The uBitx is prone to overload if there are strong signals. I have done some tests with an analog AGC detector and different FET shunts on the RX line after the relay before the first mixer.

I used a similar detector circuit as other people have published here. However, I used a BC548 as an audio amplifier instead as this is a very common bipolar transistor that is highly available with a high Hfe. The Hfe is approx 200x on the B series . The gain was set to approx  200 in a common emitter amplifier. I take the signal from before the volume control. (Be aware that the volume control pot affects the impedance a bit so the level changes even if you tap on the hot side of the audio pot ... ). The detector is two 1N4148 diodes. There is a 1uF capacitor and a 1Meg resistor to set the first order RC circuit constant.

I tried with different FETs I had laying on the shack. Since this fet is used as a is a RF shunt circuit, it is not possible to use a JFET directly since JFETs are depletion mode.

By using an enhancement mode N channel Mosfet the RF shunt presents a high impedance to the AGC amplifier / recitifier. However, the output capacitance of the RF shunt Mosfet is a bit critial. I tried with a FQP30N06L (output capacitance in the 300pF range) and a IRLIZ44N (output capacitance in the 400pF range). Those presents a too low Z to the RF path since XC = 1/(2*pi*f*C). This is around 28ohm at 14 MHz, which will cause attenuation when the AGC is not active.
Instead I used a BSS138L N mosfet that I took of a level converter board I had laying around (I cut the board in four with the SMD part on to ease soldering). I soldered the mosfet controlled RF shunt directly to the relay pin and to ground on the back side of the uBitx circuit board instead of going in on the top side of the board as some other have reported on this forum. See pic.

Shunt mosfet for RF AGC:


The AGC seems to work well even with just one shunt element.




Testing with and without AGC:





FQP30N06L
FQP30N06L

Re: Help with AGC kit wiring

Don, ND6T
 

Bill, The trace cut is shown under the manual gain control installation. You are correct with the destinations but that trace between them needs to be separated anyway and this is a convenient way to do it. The AGC board is designed so that if you use a 3-pin right-angle header instead of the 2-pin shown, you can plug the board right in. Instead of bending the middle pin to meet the traces like the others do, drill a hole through to the ground plane on the underside just large enough to accept the diameter of the pin and bend the pin over to go through it. Scrape the coating off of the area around the pin there and solder it for an excellent ground return. Between the glue holding the new header to the board, the mechanical support of the new hole, and the three solder connections it becomes nice and sturdy. If you placed that connector carefully, the new board will plug right in with enough clearance to the other parts. Bring over your twisted pair from the volume control (or the plug), and your +5 volts (like the green wire from Raduino pin 3 and decide how you would like to select your AGC release timing.
Otherwise, bring those two coaxial cable center conductors to their respective "In" and "out" holes, their shields to the center hole between, and jumper between points #1 and #2 as shown.

My best advice is to take your time. Plan a lot, Work slowly. You want to make the experience last, right? Like taking a vacation. A person doesn't want it to be over quickly!
73, Don