hi
royal mail seems to have taken a hint from dhl. i received a parcel from my daughter in new zealand and was charged.
terry gm4dso
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Re: More on troubleshooting.
Sorry I misread your email!
If Q7 is dead then you could wire a 2222 or similar and it will work.
toggle quoted message
Show quoted text
At 23-06-2017, you wrote: Hi Raj, Jerry,
I checked the voltages and Q7 was about 12.5 all the way around., So I pulled Q7 and checked with transistor tester. It thought it was a set of resistors very low ohms . (yes I checked against a good transistor)
So transistors are on order.
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Re: More on troubleshooting.
See R74 is open. Happened to me !!
If Q7 is hot then R72 is open.
Let us know.
Raj
toggle quoted message
Show quoted text
At 23-06-2017, you wrote: Hi Raj, Jerry,
I'm glad I listened to you guys and didn't take out the diodes.
Jerry, you were right about the VFO. My friends board had a nice sine wave at the output of Q7 but mine did not even though the Radino was putting out a trianglar wave.
I checked the voltages and Q7 was about 12.5 all the way around., So I pulled Q7 and checked with transistor tester. It thought it was a set of resistors very low ohms . (yes I checked against a good transistor)
So transistors are on order.
|
Re: More on troubleshooting.
Hi Raj, Jerry,
I'm glad I listened to you guys and didn't take out the diodes.
Jerry, you were right about the VFO. ?My friends board had a nice sine wave at the output of Q7 but mine did not even though the Radino was putting out a trianglar wave.
I checked the voltages and Q7 was about 12.5 all the way around., So I pulled Q7 and checked with transistor tester. ?It thought it was a set of resistors very low ohms . (yes I checked against a good transistor)
So transistors are on order.
|
I'd suggest you get an IRF510 on hand as well, they are quite cheap. ?From the datasheet, the IRF840 has a "total gate charge" of 63 nC (nano-Coulombs), vs 8 nC for the IRF510. ?That means the IRF840 would have to be driven much harder to get it to switch at 7mhz. Other issues to be aware of on the Bitx40 PA: ? ? Quiescent currents through Q13 exceed dissipation ratings of a Sot23, though a TO92 might be ok. ? ? Quiescent current through R141 exceeds dissipation rating there as well for a 1206 resistor. ? ? Q13 can blow due to energy coming in from a nearby antenna being driven from a high powered transmitter. ? ? ? ?? /g/BITX20/topic/4105366Jerry, KE7ER ?
On Thu, Jun 22, 2017 at 11:55 pm, Daniel Isaza wrote:
The driver is a 2n5109, I adjusted the current for half of that of the 2n2219 -according to the datasheet- by doubling R144, the final an IRF840, let's see how all this goes tomorrow.
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The STL files come out of Solidwork in inches.? When I bring them
into Simply3D, it has been set up to work in inches.?? There is a
GRID that the part is laying on, on the screen.? You can see the
relative size of you part laying on the grid.? It has a menu
button to convert to MM too.
Our knobs over here in the US have always been 1/4", but I am
using? an Encoder which is Metric.?? So I made it under size.? I
have a drill set, and figured it would be better under size than
over.
My next 3D project is to try ABS material.?? I have had PLA parts
MELT or Warp in the Heat.? You can't carry a PLA part in the Car
in the real hot
summer here!? For PLA I use 200C Extrude temperature and 50C Bed.
Your parts look great, the Big Knob could be a Pencil Holder!
Mike, WA6ISP
On 6/23/2017 2:19 AM, bjorn wrote:
toggle quoted message
Show quoted text
Hi Mike.
I have been using an Ultimaker 2+ printer with a 0.4mm extruder
and 3mm PLA filament. The walls are 2mm thick, which is on the
limit for the mic/phone-connectors.
I am using the OpenSCAD CAD program (box design enclosed) and the
Cura slicer.
It seems as if your dimensions are in centi-inches (!?). The hole
in your knob I guess should be roughly 6mm and it is rougly24.
So 24*2.56/100 is roughly 6.09mm.? Cura does not give you the
option to scale a .stl file though.
?
I use 1.75mm Filament.? I use Simplify3D set to 30% fill and
0.1mm layer.? I have setup in Inches, I can see relative size
when the part loads.
The big knob loads with the bottom (hollow parts up), so I
flip it with the top of the knob UP.?? I tell Simplify3D to
use SUPPORTS.
Print time is a little less than 1 1/2 Hours.
You picture looks like you were printing the smaller volume
knob.? I put a pointer on it (of a fashon).
You printer is really printing perfect.? I have never seen parts
any better!
Sounds like a Inches vs mm problem in setting?
Tell us what printer and filament you are using, the Box looks
prefect, especially with the thin walls.
They look really good.
Mike, WA6ISP
?
On 6/21/2017 2:58 AM, bjorn wrote:
here is a pic of the one I printed without checking...
On 2017-06-21 10:35, bjorn wrote:
Are you sure you sent the correct.stl files?
The one I printed came out huge and when checking the
other one a bit more carefully after slicing, it would
have been even bigger.
137.5 x 137.5 x 75 mm, 2 days and 5 hours printing time,
37m filament.
Or are your units not mm?
On 2017-06-20 15:13, Michael
Hagen wrote:
I used Black PLA and the long print time for better
print.
On 6/20/2017 6:08 AM, Michael
Hagen wrote:
Encoder or Pot
On 6/20/2017 5:51 AM, Matt
Patterson wrote:
Those look awesome. Any chance you might share?
Matt
W5LL
Sent from my iPhone 7
On Jun 20, 2017, at 7:47 AM, Michael Hagen <motdog@...> wrote:
Here are some knobs I drew up and printed. Also an LCD Bezel. I have a speaker mount and grill ready to put in too.
Mike, WA6ISP
On 6/19/2017 6:51 PM, Matt Patterson wrote:
Anyone else here have a 3D printer? Anyone found some good looking knobs for the front? I'm printing a couple I found on thingiverse right now but not sure how well they're going to work out.
73 Matt
W5LL
<RaduinoXFRONT1.jpg>
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Re: W8TEE TFT/VFO DDS adapter
Jack
any update? ?For anyone who has built the tft/before and has added the if offset. Could you share the code.?
Thanks and appreciate any help.?
Art
N2AJO
|
Hi Mike.
I have been using an Ultimaker 2+ printer with a 0.4mm extruder and
3mm PLA filament. The walls are 2mm thick, which is on the limit for
the mic/phone-connectors.
I am using the OpenSCAD CAD program (box design enclosed) and the
Cura slicer.
It seems as if your dimensions are in centi-inches (!?). The hole in
your knob I guess should be roughly 6mm and it is rougly24.
So 24*2.56/100 is roughly 6.09mm.? Cura does not give you the option
to scale a .stl file though.
?
toggle quoted message
Show quoted text
I use 1.75mm Filament.? I use Simplify3D set to 30% fill and
0.1mm layer.? I have setup in Inches, I can see relative size
when the part loads.
The big knob loads with the bottom (hollow parts up), so I flip
it with the top of the knob UP.?? I tell Simplify3D to use
SUPPORTS.
Print time is a little less than 1 1/2 Hours.
You picture looks like you were printing the smaller volume knob.?
I put a pointer on it (of a fashon).
You printer is really printing perfect.? I have never seen parts
any better!
Sounds like a Inches vs mm problem in setting?
Tell us what printer and filament you are using, the Box looks
prefect, especially with the thin walls.
They look really good.
Mike, WA6ISP
?
On 6/21/2017 2:58 AM, bjorn wrote:
here is a pic of the one I printed without checking...
On 2017-06-21 10:35, bjorn wrote:
Are you sure you sent the correct.stl files?
The one I printed came out huge and when checking the other
one a bit more carefully after slicing, it would have been
even bigger.
137.5 x 137.5 x 75 mm, 2 days and 5 hours printing time,
37m filament.
Or are your units not mm?
On 2017-06-20 15:13, Michael
Hagen wrote:
I used Black PLA and the long print time for better
print.
On 6/20/2017 6:08 AM, Michael
Hagen wrote:
Encoder or Pot
On 6/20/2017 5:51 AM, Matt
Patterson wrote:
Those look awesome. Any chance you might share?
Matt
W5LL
Sent from my iPhone 7
On Jun 20, 2017, at 7:47 AM, Michael Hagen <motdog@...> wrote:
Here are some knobs I drew up and printed. Also an LCD Bezel. I have a speaker mount and grill ready to put in too.
Mike, WA6ISP
On 6/19/2017 6:51 PM, Matt Patterson wrote:
Anyone else here have a 3D printer? Anyone found some good looking knobs for the front? I'm printing a couple I found on thingiverse right now but not sure how well they're going to work out.
73 Matt
W5LL
<RaduinoXFRONT1.jpg>
|
Alright, I'm done!
No magic smoke, no popping transistors. the regulator is regulating, all bias ok. Haven?t applied any signal yet, I'm too tired for that... enough for today. The driver is a 2n5109, I adjusted the current for half of that of the 2n2219 -according to the datasheet- by doubling R144, the final an IRF840, let's see how all this goes tomorrow. Tnx and 73! Dan.   ?
|
Many thanks Jerry and Sarma. yeah, I was figuring that out by looking at the previous stage, but I always see the 7805 with decoupling caps in both input and output from the datasheet so I kept it there. now I get it. Decoupling caps for everyone then. Thanks again. 73! Dan HK4DEI On Thu, Jun 22, 2017 at 11:48 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: Here's some thread from 2016:
/g/BITX20/topic/4105252
Farhan says it is a decoupling resistor for a driver stage.
So R144 and C142 do the same job for T6 as R135 and C133 are doing for T5 in
the previous stage,
keep power supply noise from getting into that amplifier (and vise versa).
Note that R144 is 2.2 ohms, not 2.2k. The 2n2219a sees quite a bit of
collector current.
U3 pin 3 just has a connection to the TX 12v rail, there is no cap local to
U3 shown in the schematic.
Though not a bad idea to put one there.
You might consider building the newer uBitx PA instead:
Farhan is still working on a minimal set of uBitx LPF's that meet FCC specs
for undesired emissions.
LIkewise, the Bitx PA should probably have Don Cantrell's second harmonic
fix:
Jerry, KE7ER
On Thu, Jun 22, 2017 at 09:16 pm, Daniel Isaza wrote:
R144 in parallel with a short?
|
Here's some thread from 2016: ? ? /g/BITX20/topic/4105252Farhan says it is a decoupling resistor for a driver stage. So R144 and C142 do the same job for T6 as R135 and C133 are doing for T5 in the previous stage, keep power supply noise from getting into that amplifier (and vise versa). Note that R144 is 2.2 ohms, not 2.2k. ?The 2n2219a sees quite a bit of collector current. U3 pin 3 just has a connection to the TX 12v rail, there is no cap local to U3 shown in the schematic. Though not a bad idea to put one there. You might consider building the newer uBitx PA instead: ? ?? Farhan is still working on a minimal set of uBitx LPF's that meet FCC specs for undesired emissions. LIkewise, the Bitx PA should probably have Don Cantrell's second harmonic fix: ? ? ?? Jerry, KE7ER
On Thu, Jun 22, 2017 at 09:16 pm, Daniel Isaza wrote:
R144 in parallel with a short?
|
Add an 10uF/25V? and 0.1uF at the junction of R144 and Transformer pin4.?
regards ?sarma ?vu3zmv
On Fri, Jun 23, 2017 at 9:46 AM, Daniel Isaza <hk4dei@...> wrote: Hello everyone, I'm in the process of scratch building the BitX40 PA for a DSB rig, but I don't really understand the driver stage/7805 regulator from the schematic. R144 in parallel with a short?
I edited that portion of the schematic to what would make sense to me, but I wanted to ask anyway so I don't mess up my new PA. I'm I right or am I missing something?
I found some thead from 2016 refering to that topic but still isn't clear to me.
Thanks, 73!
Dan
|
Hello everyone, I'm in the process of scratch building the BitX40 PA for a DSB rig, but I don't really understand the driver stage/7805 regulator from the schematic. R144 in parallel with a short? I edited that portion of the schematic to what would make sense to me, but I wanted to ask anyway so I don't mess up my new PA. I'm I right or am I missing something? I found some thead from 2016 refering to that topic but still isn't clear to me. Thanks, 73! Dan 
|
Re: Like to test a S-meter and soon an AGC/Tx-monitor for your bitx40?
Pavel, I looked over you Si5351 library. ?I like that it is kept simple and easy to understand. I think it could be a good starting point for a stripped down library specific to the Bitx40. It operates the VCO at the highest acceptable frequency (near 900 mhz max) that is an even multiple of the desired output frequency, The even multiple of two allows the output multisynth divider to always operate in integer mode, which reduces phase noise and simplifies programming those output multisynth registers. Given the vco frequency fvco and the 25mhz crystal oscillator frequency int_xtal, all that remains is to find non-negative integers a, b and c with b less than c such that ? fvco/int_xtal == (a + b/c)? Your code to do this has one floating point number f which is used in the computations of a, b, c. I believe that is the only place in the entire sketch where floating point is used. The amount of flash consumed would be reduced considerably if we could do without floating point.
I suggest you replace this:
######################################
#define c 1048574;
uint8_t a;
unsigned long b, fvco, int_xtal;
float f;
....
a = fvco / int_xtal;
f = fvco - a * int_xtal;
f = f * c;
f = f / int_xtal;
b = f;
######################################
with something like this:
######################################
uint8_t a;
unsigned long b, c, fvco, int_xtal;
unsigned long f; // temp variable, no longer a float
...
a = fvco / int_xtal; // find the quotient of the divide
b = fvco % int_xtal; // find the remainder of the divide
c = int_xtal;
while (c & 0xfff00000) {
b = b>>1; // divide by two till fits in 20 bits
c = c>>1;
}
######################################
(Note, I have not tried either your code or my integer only code on Si5351 hardware, I don't have access to my Bitx40.) The integer only code above should give accurate frequency synthesis better than 100ppb, similar to your original code. ?It is possible to gain another factor of 5 or so in the accuracy of the computations for (a+b/c) by going to 64 bit arithmetic, but we have already exceeded the short term stability of our 25mhz crystal oscillator using 32 bit arithmetic, so not much point.? The above code for finding a, b and c could be applied to the output multisynth dividers without any change. In this case we are looking at the ratio of the vco to the output clock, instead of vco to 25mhz crystal oscillator. On the bitx40, I'd tend to make CLK2 the VFO (as it is now), and CLK0 the BFO, each operating from a separate VCO. The third output CLK1 could operate from the same VCO as the BFO (since the BFO rarely changes in frequency) and could be set to well within a Hz of the desired frequency using the output multisynth divider.? Perhaps I don't understand what you are doing on the S meter, but looks like the two diodes are drawn backwards. Does your circuit improve on what Don Cantrell posted here?? ? ?? Don shows a 1n32, a part I am not familiar with. ?Perhaps he meant 1n34a, that germanium diode would be considerably more sensitive than a 1n4148. ? A schottky diode such as the Bat54s would also work. As Don notes, his S meter is not very accurate. Also, be aware that one S unit is a difference of 6 dB in signal strength, an S meter ideally has a logarithmic response. A really good (but relatively expensive) way to implement this would be to use an AD8307 or AD8310. Best Regards, Jerry Gaffke, KE7ER
|
Re: Like to test a S-meter and soon an AGC/Tx-monitor for your bitx40?
And the full tree of the software page is:
?
Best 73
Carlos
CX8ABF
toggle quoted message
Show quoted text
Sent: Thursday, June 22, 2017 8:44 PM
Subject: Re: [BITX20] Like to test a S-meter and soon an
AGC/Tx-monitor for your bitx40?
?
?
?
Sent: Thursday, June 22, 2017 5:01 PM
Subject: Re: [BITX20] Like to test a S-meter and soon an
AGC/Tx-monitor for your bitx40?
?
Where
is agc_software.png ?
|
Re: Like to test a S-meter and soon an AGC/Tx-monitor for your bitx40?
toggle quoted message
Show quoted text
Sent: Thursday, June 22, 2017 5:01 PM
Subject: Re: [BITX20] Like to test a S-meter and soon an
AGC/Tx-monitor for your bitx40?
?
Where
is agc_software.png ?
|
Crystal matching for the uBITX (was uBITX - A reboot of the old BITX)
?
Hi Ashhar.
?
I assume you use the G3UUR test
circuit?shown in Experimental Methods in RF design or something
similar.
If so, when calculating the values of Cm
and Lm, did you actually measure and include the stray capacitance of the
crystal holder and the wiring to the crystal switch circuitry?
Were the results significant?or are
they so minimal in effect as to be ignored?
?
Many thanks for your time
?
Slim Haines G4IPZ
?
----- Original Message -----
Sent: Thursday, June 22, 2017 5:50
PM
Subject: Re: [BITX20] uBITX - A reboot of
the old BITX
We have to first characterize the crystal. that's measure their
motional inductance and capacitance. i do this using the G3URR's method. it is
a very simple two transistor oscillator. after that, i use the same oscillator
to measure the frequency of each crystal and sort them into bins.
thanks to the bitx40 production, at least for 12 mhz crystals, i don't
have to match them. they are kept prematched in separate pouches. i just dip
into one!
- f
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Re: The $19 DIY DSP audio filter
I have not seen the video, yet, but maybe it can be put before the volume control and then the lm386 will amplify the audio?
Marco - KG5PRT?
On Jun 22, 2017 12:57 PM, "EA3IAV" < Cesarleon@...> wrote:  I don't know if you see the vid
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Re: Very high clicks after cw wiring
OK John,
never mind, good to hear you got it all working now!
73 Allard PE1NWL
|
Re: Very high clicks after cw wiring
On Thu, Jun 22, 2017 at 01:18 pm, Allard PE1NWL wrote:
Yes that's correct and as designed. So why is this an issue?
Why would you want to press PTT and close the key at the same time?
Sorry I don't understand.
I was pressing the PTT in place of having the RX-TX transistor connected. But anyway, I just finished reconnecting the transistor and everything works as it should now!!! Don't know what I did wrong before (and don't really care)! Thank you so much for your help, Allard. It's nice to know that there are still people in this world that will take a few minutes out of their busy schedules to try to help an idiot like me out!!! ? -- John - WA2FZW
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Raj vu2zap
CX8ABF Carlos Molina
Allard PE1NWL