Re: How To Do a Search for Specific Message
A standard text search using the SEARCH button on groups.io works just fine for that ? ?? /g/BITX20/messagesDon't need the entire title, just a keyword or two, spelled correctly.
On Fri, Mar 23, 2018 at 05:37 pm, Michael Shreeve wrote:
Jerry, what if you know the topic but not the message number ?
|
Re: How To Do a Search for Specific Message
Jerry, what if you know the topic but not the message number ?
On Sat, Mar 17, 2018 at 10:48 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: I first select a specific message at random, your message will do:
? ??/g/BITX20/message/44837
Then edit that number (44837) to whatever message number I want to see.
Jerry, KE7ER
On Sat, Mar 17, 2018 at 06:46 pm, Guy N7BIR wrote:
I think I¡¯m getting dumber the older I get but I can¡¯t figure out how to search for specific messages in our Group List. Putting the pound sign in front doesn¡¯t seem to work, and just putting the message number in doesn¡¯t help. Any Search gurus out there?
|
I thought I'd update this for the "junkyard" types out there.? Here is the digital rig.? RPi 3 is usually my backup APRS setup, so a Baofeng audio discombublator is on top.? FT8 QSO's from Italy, Cuba and Venezuela today from Central Texas. Audio isolator to the right (2k + 0.1uF and 600:600 transormers), I used some cheap 3.5-3.5 cables peeled and split with teeth.? Multimeter can be seen on the input side setup for current monitoring.? I didn't have any alligator clips, so I spun the wire around the multimeter leads and used the caps as clamps.? 1.8MHz high-pass on the right/top, local AM station overload. 
|
|
|
I think they redid the links to
graphics when they ported contents from hfsigs.com to
hfsignals.com.
However, they left behind the links to the old graphics which
display as broken links.? There is nothing missing, however, as
all of the graphics that relate to the wire up are there.
Mike ZL1AXG
On 24/03/18 11:06 AM, jaeinsf@... wrote:
I did see that page,
but there are quite a few broken image links connected to wiring
diagrams and such.
|
I did see that page, but there are quite a few broken image links connected to wiring diagrams and such.
|
Also
This is working for me
toggle quoted message
Show quoted text
On Fri, Mar 23, 2018 at 6:01 PM, Laurence Oberman <oberman.l@...> wrote: You can clone this Git repo
On Fri, Mar 23, 2018 at 5:36 PM, <jaeinsf@...> wrote:
Hi,
Sorry if I simply missed seeing the post, but would anyone happen to have a
link to the assembly manual. I received the BITX40 kit as a gift, but it
was missing the manual. I did see some postings with links, but the links
are broken and the help page on HF Signals' website has quite a few broken
links to images/photos.
Thanks!
|
Oh!? THANK YOU THANK YOU THANK YOU!
|
You can clone this Git repo
toggle quoted message
Show quoted text
On Fri, Mar 23, 2018 at 5:36 PM, <jaeinsf@...> wrote: Hi,
Sorry if I simply missed seeing the post, but would anyone happen to have a
link to the assembly manual. I received the BITX40 kit as a gift, but it
was missing the manual. I did see some postings with links, but the links
are broken and the help page on HF Signals' website has quite a few broken
links to images/photos.
Thanks!
|
Re: Source of small gauge shielded audio wire for a filter
#ubitx
I don't suggest you should spend money on this
but really old (pentium) desktop computers used them. The modern SATA drives don't. Try your local friendly comnputer store. I have rescued lots.
Brian VK4BAP
|
Hi,
Sorry if I simply missed seeing the post, but would anyone happen to have a link to the assembly manual.? I received the BITX40 kit as a gift, but it was missing the manual.? I did see some postings with links, but the links are broken and the help page on HF Signals' website has quite a few broken links to images/photos.
Thanks!
|
I tried to email you some pics but it seems that groups.io truncates your email address.? I did post a picture to the group though.
Mark
KC4GIA?
|
Re: Custom Graphics help for S-Meter
Vic, One last thing, I am not sure which lcd library you are using, but the Arduino supplied one has the following definition for the lcd.print method:
lcd.print(data, BASE) with:?
?
data: the data to print (char, byte, int, long, or string)
?
BASE (optional): the base in which to print numbers: BIN for binary (base 2), DEC for decimal (base 10), OCT for octal (base 8), HEX for hexadecimal (base 16).
So your statements "lcd.print(1,"? ") don't make sense in that context. Maybe you are using another library.
Also, you need to increment the cursor's position, through a loop for example, as you print the larger bars of the meter, otherwise they all print in the same spot.
73, John (VK2ETA)
|
This is my first attempt at a pcb enclosure.? Cost of the material was $12 on the auction site.? I learned a few things about measuring but am overall pleased with the result.? I will be adding slide on decals to label the controls and connections.? The paper has not come in yet.? ?I added a PTT switch and an Rf gain control (not yet implemented) on the front and a? micro USB port and audio filter switch for cw on the back.? I have a NESCAF cw filter that I will be putting in soon.? Fun stuff.? Mark KC4GIA 
|
Re: Source of small gauge shielded audio wire for a filter
#ubitx
All Electronics
Neil, W2NDG
|
Re: Custom Graphics help for S-Meter
Vic, I forgot to mention also that I had to use memcpy instead of strcpy to copy the S-meter character array into the LCD buffer string for the characters to be displayed. See extracts of the code below. 73, John Note: this is a "fat" meter with one bar per character, but it can be changed for a "thin" two bars per character like on your picture.
//VK2ETA meter for S.Meter, power and SWR
//'S' or 'P' pr 'R' then 0 to 6 growing bars, then '+' or '++' if over S9/Max Power/SWR of 10
//needle valid range 0-8
void drawMeter(int needle) {
?
? //Fill buffer with growing set of bars, up to needle value
? for (int i = 0; i < 6; i++) {
? ? if (needle > i)
? ? ? lcdMeter[i] = byte(i + 1); //Custom characters above
? ? else
? ? ? lcdMeter[i] = 0x20; //blank
? }
?
? if (needle > 7) {
? ? lcdMeter[6] = byte(7); //Custom character "++"
? } else if (needle > 6) {
? ? lcdMeter[6] = 0x2B; //"+"
? } else lcdMeter[6] = 0x20;
}
//meterType : 0 = S.Meter, 1 = Forward Power Meter, 2 = SWR Meter
void DisplayMeter(byte meterType, byte meterValue, char drawPosition)
{
?
? drawMeter(meterValue);?
? //Always line 2
? char sym = 'S';
? if (meterType == 1) sym = 'P';
? else if (meterType == 2) sym = 'R';
? line2Buffer[drawPosition] = sym;
? memcpy(&(line2Buffer[drawPosition + 1]), lcdMeter, 7);
}
?
|
Re: Common heatsink for IRD510's
#ubitx
That was my gut feeling, figured I'd best back it up somehow.
Let's assume the IRF510's tab is 1/2" by 1/2", the insulating material is 0.003" thick,
and the relatively permitivity of that insulator is 3.0
To convert to meters, divide inches by 39.37
So area = (0.5/39.37)^2 = 0.0001613 square meters, separation is 0.003/39.37= 0.0000762 meters.
Capacitance =? k * e0 * area / separation =? 3.0 * 8.854e-12 * 0.0001613 / 0.0000762 =? 56e-12 Farads
? ??
Impedance of 56 pF at 30 MHz is? ? 1/(2*pi*Hz*Farads) = 1/(2*3.14*30e6*56e-12) = 95 ohms
? ??
So the 12.5 ohm impedance presented by the output transformer should swamp any effect
that the 95 ohm capacitive impedance from IRF510 tab to ground.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Fri, Mar 23, 2018 at 12:21 pm, Jerry Gaffke wrote:
Not a problem.
Impedance from drain to ground is quite low, my guess is the push-pull output transformer gives it 12.5 ohms
because the center of the primary is effectively at ground.
|
Mike
You should be able to see this in the gallery now ... at the
bottom of the list.
I am still trying to figure out how to get these alpha order by
callsign!
Mike ZL1AXG
On 24/03/18 3:58 AM, Mharpen@... wrote:
Hello Mike,
Here are some pictures of my uBITX build.
Thanks for looking.
Mike N6CMY
|
Re: Custom Graphics help for S-Meter
Hello Vic, It could be a casting issue. Just in case see the definitions below of the special characters arrays in the uBitx software. The S meter bars using re-defined characters work fine on my display.? Also I assume you use the standard display which comes with the kit. Some display units may not have the eight user defined custom characters.? 73, John (VK2ETA)
?
//Lock (frequency) custom character
const PROGMEM uint8_t lock_bitmap[8] = {
? 0b01110,
? 0b10001,
? 0b10001,
? 0b11111,
? 0b11011,
? 0b11011,
? 0b11111,
? 0b00000
};
PGM_P plock_bitmap = reinterpret_cast<PGM_P>(lock_bitmap);
|
Re: Common heatsink for IRD510's
#ubitx
Not a problem.
Impedance from drain to ground is quite low, my guess is the push-pull output transformer gives it 12.5 ohms
because the center of the primary is effectively at ground.? (Some push pull amps power the finals through
a center-tap which is at AC ground, instead of using the extra chokes at L8, L9).
How much not a problem?
Check this out:??
Capacitances around the IRF510 gate do mean it requires more drive at 30mhz than
some of the other FET's.? But I've never heard of the drain-to-ground capacitances being
a problem.? Allison recommends extremely short source leads to a good ground plane,
and keeping the gate far far from the drain to avoid oscillations.?
She clips off the drain lead and solders any drain connections directly to the tab.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Fri, Mar 23, 2018 at 11:43 am, Al Duncan VE3RRD wrote:
This may have been answered already. The mounting tab on the IRF510 is internally connected to the DRAIN which is the output of the transistor (connected to the output transformer). Therefore would it not be hot both with 12V and also with RF; and if mounted on a common heatsink, wouldn't they be capacitively coupled together through the insulating material? Would this be a problem on the higher bands, like 10m?
I guess the way to check would be to measure power out on 10m with individual heatsinks, and then with a common heatsink. The dielectric properties of different insulators (mica, silicone, ceramic etc) could also affect things.
73? AL
|
Michael Shreeve
Neil Goldstein