Date   
Re: uBitx Easy Digi hookup advice? #ubitx

Doug W
 

Re: Alternate pop fix...

 

I built up Allison's (KB1GMX) anti-pop circuit on a small piece of single-sided copper-clad board, using Manhattan building techniques and MEPADS (www.qrpme.com
and I must say that it does an excellent job of suppressing the pops on both the RX to TX and the TX to RX transitions.

The idea of using the second diode connected to the Raduino T/R line is brilliant as it gives the circuit a head-start on muting the audio before the relays are engaged on TX.
Bravo ! 

I ended up having to play with the value of the capacitor as I was still getting some noise on the TX to RX transition. For whatever reason I ended up with an extra
1uF paralleled with the specified 0.1 uF. I haven't really had a minute to go back and look in detail at why this was necessary, but the end result is that I can now use
headphones with my uBITX without hurting my ears so that is all that matters. 

I have attached a picture of my little board. 

BTW, since I do plan on using the rig for CW and thus did want to preserve sidetone, I replaced R70 (100 ohms located on the far right edge of the board about half way back) with a 1K resistor as Farhan has done on the V4 boards.  

I connected the drain on the 2n7000 to the M2 end of R70 (the end furthest back). 
I connected a ground wire (twisted together with the above wire) to end of D8 closest to the right edge of the board (D8 is very close to R70).

The 5 v T/R input  is connected via a single wire to the junction of C150 & R150 on the back left corned of the board (between relay K1 and P1 - the power connector). 

The TX input  is connected to the end of C150 closest to D13 (this is 12v on TX). 

Cheers

Michael VE3WMB 

P.S. BTW the bulges in the wires are ferrite beads covered in heat shrink tubing.
Overkill, but I like to try to keep RF out of where it doesn't belong and I ended up with a life-time
supply of mix 43 beads as I needed one and had to order 100 so I figured that I might as well use them ;-) 

uBitx Easy Digi hookup advice? #ubitx

kj6etl
 

I want to add the digital modes to my uBitx. Before I reinvent the wheel, I would like to know how to go about connecting the audio in an output to the uBitx. Do I put a relay or multi-pole switch can I do something about keeping the audio levels consistent when switching from Voice to digital communications?
Are there points on the board where I can directly tap the "Easy Digi" into?

Re: Stray RF?

M Garza <mgarza896@...>
 

Hi Jay,
I actually have not cut any of the factory cables.  I grouped them and put the clip on ferrite on them.  I did not include the antenna (used some small coax for that).  I will be trimming the cables, once I know what case I will be using and I am done with my mods.  The ferrite keeps my display from going blank and the NANO from resetting.  It was getting really annoying.

Marco - KG5PRT 

On Wed, Jun 20, 2018, 10:53 AM Jay - WS4JM <ws4jm@...> wrote:
Where to add the ferrite? On the antenna leads?

Re: Output power

Jack, W8TEE
 

HA! We ran 200W into it for about 5 minutes and, while it could probably make French Fries, nothing was damaged. Still, we rate it at 150W for use as a DL or a parttime hand-warmer otherwise.

Jack, W8TEE

On Wednesday, June 20, 2018, 12:21:03 PM EDT, Doug W <dougwilner@...> wrote:


On Wed, Jun 20, 2018 at 09:04 am, Jack Purdum wrote:
20 3W 1000Ω resistors sitting in a bath of mineral oil
when I saw that in your book I remember thinking if my boiler quits in the middle of winter that would make a nice backup!
 
--
www.bitxmap.com

Re: Homebrew from scratch #ubitx

James Lynes
 

I've been a little surprised that someone hasn't already defined and published a "Hambus".

Maybe base it on 20 pin double row(40 pins) m/f 0.1 pitch connectors. Define pins for RF, IF, AF, I, Q, Controls, and multiple power and ground traces. Layout mother boards in assorted  slot counts.

James
KE4MIQ

Re: uBITX Version 4 first attempt #ubitx-help #ubitx

Ashhar Farhan
 

Rick,
I will try to record a video of how to do it. 
- f

On Wed, 20 Jun 2018, 21:59 Richard, <richard@...> wrote:
Mr. Farhan,

I love the radio and I am enjoying the process of learning how more of this works as I go!  Sorry some people took my thread with 2 questions and turned it into a soapbox...  

Can someone who has had luck with a V4 calibration using the stock firmware lend me a little advice?  In my original questions, I explained my confusion!

Thanks.
Rich
--
Richard
KC7DDW

Re: uBITX Version 4 first attempt #ubitx-help #ubitx

Kunjani Ol <loot@...>
 

W8TEE has summed things up well.
I wouldn't have used such a polite term as bullcrap!
As for trading standards closing him down if he had been in the uk, totally delusional, trading standards can READ.

As for the post and breaking, I get parcels from the east nearly every day, I order quite often from FoxDelta in India, and I have three uBITX, and the only thing I have had damaged in transit in the last few yeaRS was an Icom 736 totally destroyed by UPS, a local delivery.

It reminds me of the drunk in the room saying "everyone in here is drunk, they are all swaying"

Re: Audio feedback during transmit? #ubitx

 

Well, this has been interesting...  I started playing with a relay, which worked, but on the air testing with a local amateur made me wonder if "maybe" I had the radio setup improperly. He said my audio sounded "Weird and weak".
So I started using uBiTX memory manager. I read many of the calibration procedures and played with some of the calibration and BFO numbers.  Once I got the radio setup to my liking, the audio "feedback" during transmit went away!  Am I crazy, or was this part of the problem? 
Your mileage may vary,
Jim W0CHL

Re: uBITX Version 4 first attempt #ubitx-help #ubitx

Richard
 

Mr. Farhan,

I love the radio and I am enjoying the process of learning how more of this works as I go!  Sorry some people took my thread with 2 questions and turned it into a soapbox...  

Can someone who has had luck with a V4 calibration using the stock firmware lend me a little advice?  In my original questions, I explained my confusion!

Thanks.
Rich
--
Richard
KC7DDW

Re: I'm really stuck! No Xmit Pwr. #ubitx

Howard Fidel
 

Chip:
It you like, I can walk you through some diagnostics over the phone, provided your scope has sufficient bandwidth to use it to trouble shoot. What is the bandwidth of your scope, and do you have a 10X probe?

Howard

On 6/20/2018 11:26 AM, Arv Evans wrote:
Chip  

It is possible to use your oscilloscope to trace signal flow, but the scope needs to have adequate bandwidth for the signal being viewed.  A diode detector (1N4148 diodes work fine for all but very low level testing) is faster and more convevient for transmit side signal tracing.  

Arv
_-_




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: "Latham, Chip" <clatham@...>
Date: 6/20/18 8:35 AM (GMT-07:00)
Subject: Re: [BITX20] I'm really stuck! No Xmit Pwr. #ubitx

I will see if I can come up with a germanium diode. 
I do have a digital storage o'scope... trying .
Pay day is a ways off and I am tapped out so no more orders to the parts place this week. but have a wealth of junk just will take a bit. 
I appreciate everything that everyone is suggesting.
Thank you
Frustrated Ham
N5FJK
Chip 


Re: Output power

Doug W
 

On Wed, Jun 20, 2018 at 09:04 am, Jack Purdum wrote:
20 3W 1000Ω resistors sitting in a bath of mineral oil
when I saw that in your book I remember thinking if my boiler quits in the middle of winter that would make a nice backup!
 
--
www.bitxmap.com

Re: Understanding Spurious Emissions

Howard Fidel
 

Very true!

On 6/20/2018 11:30 AM, Arv Evans wrote:
Most who have performed detailed tests seem to indicate that unwanted spurs are a problem only if AF or RF drive levels are set too high.  On CW the uBITX does not use modulation and thus has low spurious output.

Arv
_-_



Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Howard Fidel <sonic1@...>
Date: 6/20/18 8:36 AM (GMT-07:00)
Subject: [BITX20] Understanding Spurious Emissions

There have been a few threads discussing how the uBitx has spurs that may exceed the spur amplitude allowed by law. Ham radio is regulated by Part 97 of the FCC regulations. The allowed spur amplitude for frequencies below 30 MHz is in section 307. I have reproduced paragraph D below:

(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement. 

The first interesting thing about these regulations is that they are not consistent across time. If you have a transmitter that was installed before April 15, 1977 it is not even regulated for spurious emissions. Before 2003, the spurs were limited to 50 mW max and must be at least 40 dB below the carrier power. Today, the constraint is -43 dB below the carrier power. So if you have a 1 KW transmitter, you are allowed to have spurs that do not exceed 50 mW, hence the earlier 50 mW limit. To keep things in perspective, if your uBitx puts out 5 watts of power on 15 meters, 50 mW of energy would be only 20 dB down from your carrier. 
So if you use your uBitx barefoot (i.e without a linear amp) although you may exceed the allowed spur amplitude on the 15 and 10 meter bands, your radiated power level will be so low that it is virtually impossible for it to interfere with other services, and that your radiated emissions maybe in line with what other ham operators are radiating legally. Also, I might add that these spurs are not consistent in amplitude  from unit to unit. I measured mine as being in compliance, but right at the -43 dB limit. Furthermore, the testing is done into a dummy load. When connected to an antenna, your SWR at the spur frequency is probably high, so you are radiating even less energy. 
My personal take away from this is that although the uBitx may at times not be in technical compliance with the regulations, operating at frequencies above 21 MHz, it is in compliance with the intent of the law, which is to prevent interference with other services. You can help your uBitx stay in-compliance by not over driving your audio, and by only operating it barefoot above 21 MHz. 
So, the bottom line is you should not use the uBitx above 21 MHz if you are concerned with the letter of the law, but you may use it if you are concerned with complying with the intent of the law.

Howard


Re: uBitx V4 linearity mod in final audio amplifier #ubitx

Tim Gorman
 

Why not just feed each base with a capacitor from the pre-driver and add a 1k resistor to gnd from the base of the pnp?

Then the biasing isn't a problem.

tim ab0wr

Re: Output power

Jack, W8TEE
 

The DL I mentioned the other day has this resistor pack:

Inline image

in it, which has 20 3W 1000Ω resistors sitting in a bath of mineral oil. Overkill by a factor of 20 for QRP, but great if you work both QRP and a standard 100W transceiver. You could build it without the OLED and Nano watt meter, but for $20 for everything, why not? (Details will be in Nov, 2018, QST.)

Jack, W8TEE


On Wednesday, June 20, 2018, 11:54:49 AM EDT, Doug W <dougwilner@...> wrote:


On Wed, Jun 20, 2018 at 08:36 am, ajparent1/KB1GMX wrote:
You need a load (10W) such as six 300 ohm 2 watt metal film resistors in parallel
and a 1n5711 diode to rectify the RF.
If anyone is looking for a kit here what I have https://qrpguys.com/12w-dummy-load-power-meter  sure you could piece together the parts for a little less but I didn't have everything on hand.
 
--
www.bitxmap.com

Re: Understanding Spurious Emissions

Arv Evans
 

Most who have performed detailed tests seem to indicate that unwanted spurs are a problem only if AF or RF drive levels are set too high.  On CW the uBITX does not use modulation and thus has low spurious output.

Arv
_-_



Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Howard Fidel <sonic1@...>
Date: 6/20/18 8:36 AM (GMT-07:00)
To: BITX20@groups.io
Subject: [BITX20] Understanding Spurious Emissions

There have been a few threads discussing how the uBitx has spurs that may exceed the spur amplitude allowed by law. Ham radio is regulated by Part 97 of the FCC regulations. The allowed spur amplitude for frequencies below 30 MHz is in section 307. I have reproduced paragraph D below:

(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement. 

The first interesting thing about these regulations is that they are not consistent across time. If you have a transmitter that was installed before April 15, 1977 it is not even regulated for spurious emissions. Before 2003, the spurs were limited to 50 mW max and must be at least 40 dB below the carrier power. Today, the constraint is -43 dB below the carrier power. So if you have a 1 KW transmitter, you are allowed to have spurs that do not exceed 50 mW, hence the earlier 50 mW limit. To keep things in perspective, if your uBitx puts out 5 watts of power on 15 meters, 50 mW of energy would be only 20 dB down from your carrier. 
So if you use your uBitx barefoot (i.e without a linear amp) although you may exceed the allowed spur amplitude on the 15 and 10 meter bands, your radiated power level will be so low that it is virtually impossible for it to interfere with other services, and that your radiated emissions maybe in line with what other ham operators are radiating legally. Also, I might add that these spurs are not consistent in amplitude  from unit to unit. I measured mine as being in compliance, but right at the -43 dB limit. Furthermore, the testing is done into a dummy load. When connected to an antenna, your SWR at the spur frequency is probably high, so you are radiating even less energy. 
My personal take away from this is that although the uBitx may at times not be in technical compliance with the regulations, operating at frequencies above 21 MHz, it is in compliance with the intent of the law, which is to prevent interference with other services. You can help your uBitx stay in-compliance by not over driving your audio, and by only operating it barefoot above 21 MHz. 
So, the bottom line is you should not use the uBitx above 21 MHz if you are concerned with the letter of the law, but you may use it if you are concerned with complying with the intent of the law.

Howard

Re: I'm really stuck! No Xmit Pwr. #ubitx

Arv Evans
 

Chip  

It is possible to use your oscilloscope to trace signal flow, but the scope needs to have adequate bandwidth for the signal being viewed.  A diode detector (1N4148 diodes work fine for all but very low level testing) is faster and more convevient for transmit side signal tracing.  

Arv
_-_




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: "Latham, Chip" <clatham@...>
Date: 6/20/18 8:35 AM (GMT-07:00)
To: BITX20@groups.io
Subject: Re: [BITX20] I'm really stuck! No Xmit Pwr. #ubitx

I will see if I can come up with a germanium diode. 
I do have a digital storage o'scope... trying .
Pay day is a ways off and I am tapped out so no more orders to the parts place this week. but have a wealth of junk just will take a bit. 
I appreciate everything that everyone is suggesting.
Thank you
Frustrated Ham
N5FJK
Chip 

Re: Output power

Doug W
 

On Wed, Jun 20, 2018 at 08:36 am, ajparent1/KB1GMX wrote:
You need a load (10W) such as six 300 ohm 2 watt metal film resistors in parallel
and a 1n5711 diode to rectify the RF.
If anyone is looking for a kit here what I have https://qrpguys.com/12w-dummy-load-power-meter  sure you could piece together the parts for a little less but I didn't have everything on hand.
 
--
www.bitxmap.com

Re: uBITX Version 4 first attempt #ubitx-help #ubitx

Ashhar Farhan
 

I am reading this thread. I really have no comments except that there is no objective measurement or audio clip that i can comment upon. Hence let me make some general comments.
As old timers will testify, i never recommend, leave alone ship a circuit that i havent built at least twice and operated them on air for at least three or four mornings. I did extensive on-air tests as well as distortion measurements on the new  audio amplifier before shipping it out.
The thing that I have been unhappy about is that I had to reduce the overall gain. I took a decision to not revise the circuit too much but fix the excessive gain that can distort without the AGC. If we had the luxury of AGC, we could have lived with higher gain. The radio is now optimised to work well into 21 mhz. At 28 mhz, the gain is enough for headphone operations but speaker output will work only in a quite room. 
I continue to use the v4 regularly with FT8 as well as local ragchew on 40 meters. I have asked production to ship me a latest batch board to test it out. This is just in case there has been a mistake in terms of change of component values. I will report. This back in a day. 
- f

On Wed, 20 Jun 2018, 20:54 Jack Purdum via Groups.Io, <jjpurdum=yahoo.com@groups.io> wrote:
"...that it will be required by the builder to almost replace every component to make the rig work."

Bullcrap, and you know it!

"No one can expect a builder to rip out components and bodge the pcb to get it to work. This is not a user friendly board as it is all surface mounted and if you dont have good eye sight and the correct equipment then it will end up as a bin job!!"

More bullcrap. First, all 5 of mine worked "out of the box" and, add about three or four thousand more buyers who also have it working without mods, and I'm pretty sure you screwed something up. Second, I'm 75 with a sad excuse for eyesight, yet with a headset of magnifying lens, I've found that I can solder a 10-pin Si5351 chip the size of a match head onto a PCB. Have you even tried working with SMD parts? You knew before you bought the two rigs that they contained SMD parts and that many mods have been made. Sounds to me like you ignored your own research. Whose fault is that?

"I paid good money for a Bitx 40 and a Ubitx V3 and both were received damaged, a replacement Bitx was sent and that was also received damaged."

Evidently you didn't learn your lesson on the first one and should have paid the DHL fee on the second. I've purchase 5 units and everyone of them arrived in good shape, and the US is farther away the the UK. As someone once said: "Insanity is doing the same thing over and over and expecting different results". Seems to me to be sort of a "fool-me-once" situation on your part.

Jack, W8TEE

On Wednesday, June 20, 2018, 9:57:33 AM EDT, Ray Koster via Groups.Io <raykoster=talktalk.net@groups.io> wrote:


I think that Andy is correct in thinking why he should have to do all these mods to this kit!! I also have purchased and built several kits in the past and have never had to do the scale of modifications that are now required to get this kit to work correctly. It was never disclosed on the HF signals website that it will be required by the builder to almost replace every component to make the rig work and be legal on the air.

Why are you Guy's sticking up for Farhan, when he does not come forward and hold his hands up and say that the kit should have never gone to market.If this was UK produced ,then Trading Standards would have closed HF Signals down long ago!!!

No one can expect a builder to rip out components and bodge the pcb to get it to work. This is not a user friendly board as it is all surface mounted and if you dont have good eye sight and the correct equipment then it will end up as a bin job!!

Also most builders do not have the correct test equipment to make tests to insure that after all these mod's, they are legal when on the air with this kit

My biggest beef about all this is that HF Signals cannot deliver a kit to me that is not damaged in the post and please dont tell me I have pissed of the postman, My postman is a nice guy and so are the staff at the sorting office and India to the UK is a very long way

I paid good money for a Bitx 40 and a Ubitx V3 and both were received damaged, a replacement Bitx was sent and that was also received damaged.

When I pay good money, I expect to receive the goods in a usable state and then I do not expect to have to then remove and replace most of the components at my expense, and probably have to wait weeks for these new components to come in, just to get it to work correctly

Firmware updates are acceptable as the nature of the code can led to bugs creeping in and this is a very easy thing to do and does not require butchery of the pcb

Ray Koster G7BHQ

Re: RF power chain mods and improvements..

ajparent1/kb1gmx
 

On Wed, Jun 20, 2018 at 08:38 am, M Garza wrote:
2N5770
I took a look at the datasheet.  It might be a good part to try.  I'd be curious to hear if they work for you.

Hint if you go with 2n5109s due to their size its easier to put on on the top and the other on the bottom.

Despite its oddities its an interesting radio to work with.

Allison