Date   
Re: Ubitx - using Amateurradiokits.in AGC #ubitx

Dan Schaefer
 

Thank you.  The picture helps confirm I put the parts in the right places.  Appreciate the clear picture. Harder to see on the manual  copies. 

Dan.  W3BU




On Feb 23, 2019, at 2:25 AM, Wayne Leake <wayneleake@...> wrote:

Just thought, I should have added this picture of a finished board, showing the parts nicely.

<dummyfile.0.part>

Dang big picture.




--
k

Re: ubitx schematic cleanup #ubitx

Ted
 

I'll wager those extra final section reservations will accommodate a pair of 
 RD15HVF1, subject to checking pinout. I know they have 2 of the leads reversed as compared with the IRF510's.  The former are true RF devices and are rated to do well at 12v.

I'll let the class know how that works out, when my pair come in and I shove them into a version 5 board.




Ted
K3RTA

Re: ubitx schematic cleanup #ubitx

Curt
 

Evan

thanks for many thoughtful and useful posts here to this list.  they certainly have helped me.  

the 2 different PA's are alternatives (one of our local builders questioned the same thing).  I have no clue why the designer left them there even in v5 -- but it does keep us on our toes.  I haven't researched those caps -but I would imagine there is a place for them in the layout - for those making modifications.  

As you know Farhan I trust stays quite busy - otherwise we would not be blessed to have a ubitx.  What might seem small to us may not fit into his schedule.  

Glad to journey with you.  I hope to report when my ubitx gets measured it passes spurious, and I am toying with a couple of the AGC circuits (I now realize I may have installed them wrong - yes when the style of the schematic, that leaves off the off-board components confuses me!)

73 Curt WB8YYY

ubitx schematic cleanup #ubitx

Evan Hand
 

Not sure who is the correct person to send this to in a private email, so created a new thread for all to see.

When I first started on the ubitx journey, I was often confused by the differences between what was on the published schematic and what was actually provide.  Currently there are 2 that I am aware of:
1 - Q942 and Q952 do not exsist, and I am not sure would work as shown (most times you need some sort of resistor or other feedback to keep 2 parallel active devices sharing the load).  Regardless, they are not there
2 - C210 and C216 also do not exist (though at least they do have a 0 as the value}.

I know that these are minor points, however there is enough things to learn without having to verify that the schematic is in fact what is on the board.

This should not take that much effort, as it is just removing the components from the original and saving a new PDF.

The above are my opinions only
73
Evan
AC9TU 

Re: Bitx-40 Arrived Today - Advice Solicited on My Plan

Pat Anderson <anderson5420@...>
 

Thanks, good suggestions all. I assume you do as much of the wire up as possible on the bench, and then put it in the case?


On Fri, Feb 22, 2019 at 7:32 PM Curt via Groups.Io <wb8yyy=yahoo.com@groups.io> wrote:
Pat

Just a few things. I would do some partial assembly of the raduino, main board etc to get a feel for things. Many in qrp community like bnc, of course idea is to do it the way you want it. For some folk in the world, that ptt and microphone element get them on the air. Yes normally open ptt.

I suggest wiring up both headphone and speaker. You may find audio output lacking to drive a speaker. Some folk use an external amplified speaker, or add an internal audio amplifier.

I suggest you visit some websites from around the world that describe bitx assembly.

Curt

Re: Bitx-40 Arrived Today - Advice Solicited on My Plan

Pat Anderson <anderson5420@...>
 

There were eight of them, and they were all the same size. Those look like the standoffs the come with the ubitx kit. I watched a video of a guy assembling that kit with a custom ubitx case, and he had a hard time figuring them out. I do not see how those would attach the display to the raduino, maybe somebody could post a photo of how they used these standoffs to do that.


On Fri, Feb 22, 2019 at 9:43 PM Wayne Leake <wayneleake@...> wrote:
 Are these what you mean by stand offs?
 4 are used to mount the main board, and the other 4 to mount the display to the raduion.

image.png
Plain and simple.
 

Re: Bitx-40 Arrived Today - Advice Solicited on My Plan

Pat Anderson <anderson5420@...>
 

I just went to eBay and searched for 10 turn 10k pots. This was recommended by somebody here to make tuning more precise. There are dozens of them. Same with the speaker, momentary switch and SO-239. Bear in mind, I may not use any of them and just build with the supplied parts. TThey were all dirt cheap.The part that came with the kit I am pretty sure I am not going to use is the supplied PTT switch.


On Sat, Feb 23, 2019 at 7:50 AM SAM R BURNES via Groups.Io <sburnes=icloud.com@groups.io> wrote:
Just getting started on my 40. Is there a preferred pot? 

Would you please share the dealer and part number for the pot?

Sam

WY8V


On Feb 22, 2019, at 10:43 PM, Wayne Leake <wayneleake@...> wrote:

 Are these what you mean by stand offs?
 4 are used to mount the main board, and the other 4 to mount the display to the raduion.

<image.png>
Plain and simple.
 

Re: Any Gerber Experts Round Here? #kicad #ubitx

Tom, N8TPN
 

I know that this is an old thread, but it was never clear exactly what the files being converted were for...was this a conversion of the posted M0HYT thru-hole uBitx gerber files?

From the tone of the posts, it sounds very similar to the problems I ran into when trying to get the M0HYT boards fabricated at a PCB vendor.

All the vendors I tried said that there was a problem with the drill definitions.

If these are the files for the M0HYT uBitx, was any thought given to posting them to the files area here so that others could take advantage of the converted gerber files?

I for one would really appreciate getting my hands on gerbers for the M0HYT thru-hole uBitx that are acceptable to the PCB vendors in China.

Thanks and 73,

Tom - N8TPN

Re: Bitx-40 Arrived Today - Advice Solicited on My Plan

SAM R BURNES
 

Just getting started on my 40. Is there a preferred pot? 

Would you please share the dealer and part number for the pot?

Sam

WY8V


On Feb 22, 2019, at 10:43 PM, Wayne Leake <wayneleake@...> wrote:

 Are these what you mean by stand offs?
 4 are used to mount the main board, and the other 4 to mount the display to the raduion.

<image.png>
Plain and simple.
 

Re: Voltages at test points on V4 boards #bitx40help #calibration

 

Scott,

I have test instruments that can do what you suggest but the majority dont.

Diode detectors will only be useful in the later stages of the final amp as earlier stages run at
minuscule signals like -10-15dbm at the input of the power amp and -30-35dbm after the 45MHz
filter!

I recommend trying a log amp like AD8307 that outputs 0.5-2V, I will prefer an analog meter as
an indicator for RF level. It can read very small signals. Ready boards on the bay. Buy one with
a 5V regulator then you can connect to any supply. You can get a better one from the Greek
site of Makis - https://www.sv1afn.com/ I bought a board of AD8307 buffered with opamps etc.

Raj

At 23-02-19, you wrote:
Hi Raj
This is even more useful. Could we not measure those RF voltages with a regular RF probe (e.g., containing a germanium diode to rectify them to DC) and DVM, or an oscilloscope with bandwidth in HF range to measure RF voltages directly?

If anyone knows what the RF readings should be at all the numbered test points for a v4 board, let me know. I would like to compile a master list of DC and RF measurements to give a "physical check-up" to my v4 board. Would also be useful to know the expected waveform of the RF voltages at the numbered TPs (to confirm with 'scope).

This can also be a good baseline for assessing before and after conditions when doing mods and fixes, and a good learning tool.

I haven't seen such a master list yet. Once it's put together, I will of course share with group!
73. Scott VO1DR

Re: Voltages at test points on V4 boards #bitx40help #calibration

Scott Schillereff
 

Hi Raj
This is even more useful. Could we not measure those RF voltages with a regular RF probe (e.g., containing a germanium diode to rectify them to DC) and DVM, or an oscilloscope with bandwidth in HF range to measure RF voltages directly?  

If anyone knows what the RF readings should be at all the numbered test points for a v4 board, let me know.  I would like to compile a master list of DC and RF measurements to give a "physical check-up" to my v4 board.  Would also be useful to know the expected waveform of the RF voltages at the numbered TPs (to confirm with 'scope).

This can also be a good baseline for assessing before and after conditions when doing mods and fixes, and a good learning tool.

I haven't seen such a master list yet.  Once it's put together, I will of course share with group!
73. Scott VO1DR

Re: Ubitx - using Amateurradiokits.in AGC #ubitx

Wayne Leake
 

Just thought, I should have added this picture of a finished board, showing the parts nicely.


Dang big picture.




--
k

Re: CLK 0

jim
 

well, just because I can? ..I know "smart-ass answer", but I bought the ubitx to play with so ...and I don't like the sound with the clk0 running on it on AM

Jim

On Friday, February 22, 2019, 12:17:55 PM PST, Don, ND6T via Groups.Io <nd6t_6@...> wrote:


Jim,x

Why a separate AM detector? When the reference oscillator is calibrated then you just tune to the carrier frequency and it is zero beat. I've been listening to broadcast on the BITX since I first went digital with them. It works better than the normal AM detector since the carrier isn't necessary. No distortion. Exalted carrier.
Biggest issue is the narrow filter band pass. But it's good enough for my ears.
73,
Don

Re: CLK 0

jim
 

with regards to what?

On Friday, February 22, 2019, 11:01:56 AM PST, Robert McClements <gm4cid@...> wrote:


Jim,

Would you kindly share your findings.

73, Bob GM4CID

Re: Ubitx - using Amateurradiokits.in AGC #ubitx

Wayne Leake
 

 Also, I forgot, here is the board layout for the board that comes with the kit.
 I inly have the parts, but will put them on a perfboard.

image.png

Re: Ubitx - using Amateurradiokits.in AGC #ubitx

Wayne Leake
 

 Here is the scematic.

image.png

-

Re: Ubitx - using Amateurradiokits.in AGC #ubitx

Wayne Leake
 

 here is a partial schematic for the BITX40 from amateurradiokits.in.
 You can see where the AGC ic connected to the first RX IF amp.


image.png


I'll look for the schematic for the AGC kit for the same, at least theone I have parts for.

Re: The new uBITX boards are here

tedlong17@...
 

Somewhere, in the loft of the garage, above the shack, rests my old HP-65. I lived on ramen and cheap hamburgers for several months,
scrimping and saving for that freshman EE major's dream, complete with mag stripe program packs and printer, for $750.00 (1976 USD).
I'm posting this from a $35 Raspberry Pi, that's also running the Arduino IDE as I tweak my uBitx. Guess being an early adopter has it's pitfalls. ;>}.
73's DE
KD0KSP
Ted

Re: Bitx-40 Arrived Today - Advice Solicited on My Plan

Wayne Leake
 

 Are these what you mean by stand offs?
 4 are used to mount the main board, and the other 4 to mount the display to the raduion.

image.png
Plain and simple.
 

Re: DAC/ADC for PI, might be useful here

James Lawrie
 

Been using HIFI Berry + and RTC for a few years now for Audio Playback just thought others might be interested since they now have DSP and ADC versions. The only other cards I've seen where either low bit rate or audio only. Plus they ship quick and build quality so far great, have to admit I've seen a few other High End cards out there but way too expensive. Just wish they included RTC Chip on ADC Card.