Raj,
You're right. ?Reversed polarity would not smoke D6.
When looking for D6 I figured it was the one across K2 as the schematic is not terribly clear there.
But I see now that the one across K2 is D8. ? ?
Not clear why D6 would smoke unless there was a screw dropped into the board or something.
If the LM7805 and LM78L09 regulators avoid passing negative supplies somehow,
might not be just too much damage from reversed power.
But I don't see anything in the LM78** datasheet suggesting that is the case.
Would be interesting to see what they do.
Just about any regular diode would do as a quick replacement for D6, characteristics are not critical.
Could be an axial leaded 1n4007 power diode, for example.
Same with the other diodes in the rig except for those in the two mixers.?
Jerry
?
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On Fri, Jun 9, 2017 at 07:50 pm, Raj vu2zap wrote:
If D6 smoked then the relay K1 would have switched to TX mode.
IF the polarity was reversed then D7 would have smoked.
Most of the transistors are safe from polarity reversal due to the diodes in series with power / collectors.
?
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Re: BITX40 Serial Numbers
Hello Michael, could you tell me where you got that case, I really like that
Thanks
Joe,
KD2NFC
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Re: Making PSK31 Contacts
Great, Thanks for the advice. I have several CPU heatsinks so I may dig one of them up and make it fit. The transistor is isolated from the back chassis and the heatsink with a mica insulator and has heatsink compound between all the mounting surfaces. I was just surprised that the heatsink got hot. I had assumed the chassis would have soaked up most of the heat. 
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Re: Dual Band BITX40: Automatic Switching from 40m to 80m
Yep the QRP Labs VFO does + or - offset, + offset gives USB if you remove C91 and C92. See my blog for info on that too using the Jt65 link below. -- Ryan Flowers W7RLF
?
?<-- Learn how to go digital on the BITX40
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Re: Other 2 line displays
I got this one. They took so long I asked Ebay to step in. It arrived at the very last moment. Then the replacement they sent on their own came two weeks after that. Now I have two.
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Jerry,
If D6 smoked then the relay K1 would have switched to TX mode.
IF the polarity was reversed then D7 would have smoked.
Most of the transistors are safe from polarity reversal due to the diodes
in series with power / collectors.
Raj
At 09-06-2017, you wrote:
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It appears to be the same part
as the 1n4148w diodes used in the diode ring mixer, in an SOD-123
package:?
However, if you reversed the power supply leads into your Bitx40, you
could have blown just about all of the semiconductors on the board.
You might wind up having to buy a new Bitx40, use this one for spare
parts.
Another issue is giving a few volts over 12v, since Q13 and R141 are
already a bit beyond their maximum dissipation limits.
Adding an LM2940T-12 as per??
/g/BITX20/message/26492
would protect from both reversed supply leads and voltages beyond
12v.? It also limits current to something manageable.
Perhaps something like this should be included in the board layout if it
rolls (or in the uBitx).
Jerry, KE7ER
On Fri, Jun 9, 2017 at 03:55 am, <mattcarus@...> wrote:
- Powered up my BITX40 last night and some smoke escaped from D6 :( - I
assume it'll need replacing which is fine, can anyone tell me what
package size it is?
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Re: Standoffs for mounting the board
I used plastic standoffs with a flat foot, and some double sided foam mounting tape to mount it in a holiday tin. Like the stuff on the back of a breadboard. Here is a link to what I have, and the feet are half inch. I got some bigger ones but the post was too big for the BITX holes.
This next one is the ones that are too big.
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Re: add yourself to the new BITX operators map
Jerry and all,
I having trouble standing on any base, and I have verbal blocking, and word finding problems at times, so off base works for me fairly often. Antarctica probably not.
I will explain why I think modded or unmodded, should probably be the color difference (and no, I don’t think anyone would want another place to update every time they turn on their radio)… but, back to the why…
Lets take me….I am an Extra, I can go anywhere, but I don’t know Didley….as far as anything current in Radios….now I have an Electronics background that goes back to a few months out of high school when I stepped on a fllghtline and learned what a magnetron was. ?
But, I am learning as I go in this stuff, like anyone else who got their first Amateur Lic last October, and their first HF radio when my BitX40 arrived from India a couple of months ago. ?I have a Grand total of two unique QSO’s, but three with W1LY (as does a lot of others). So, I know W1LY is doing something, probably different than me. ?If we mark as Stock, no mods, and what likely Antenna is…..Real Novices like me know what you old timers don’t have to even think about. If it is marked as Modded….well then if I want to find out just what someone has done, I can try a different route to find out. ?Another on/off switch in the data I would like to see, is PA voltage, Me (whatever my HF jump start battery puts out) ?so I would like to know if someone always runs 12volts, or do they ‘pump it up’…
I think we have a unique opportunity to actually compare apples to apples and oranges to oranges, without jumping thru a lot of hoops….
But, then….before diagnosis, I coded on AS/400’s.
KM4YEC Craig
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On Jun 9, 2017, at 7:38 PM, Jerry Gaffke via Groups.Io < jgaffke@...> wrote:
Yup, great idea! Thanks for setting up the map. If you're in antartica and there's lots of room around your call, then probably ok to have more than just your call on the map pin. ?But if there's 20 other pins on top of yours, best to stick with just a call. ? Fine with me if you put any info whatsoever in the pop up tag. A first name would be friendly. Maybe a URL to a website fully describing all the stuff you have done to your rig. But I'm not going to update the map every time I try a new antenna or PA supply voltage. Though might give some indication if I ever get one of these: ?Just so you know, my rig has been modded with a ?custom front panel. ?Back panel too. If for some obscure reason you need to know my license class, you'll have to check in with I'd prefer an uncluttered basic map. Maybe there is something meaningful we could do with the colors, but I can't think of what that would be. Color preference, perhaps. I like blue.? Jerry, KE7ER ? ?Flora OR On Fri, Jun 9, 2017 at 03:22 pm, Craig Thibodeaux wrote:
1. Call for what unique ID’s others would like to see
?
Stock
Modded (how)
Antenna (details)
Lic Class
Region is already shown on map (after thinking about it)
First Name?
?????
?
2. ?After agreeing to a list, then decide how to implement, within limits of Pins, Title box, Description Box
?
3. After this map fills up…..uniformity will make it usable, requiring agreeing on abbreviations, color codes, placement, order, etc…..
?
Again, Great idea Doug
?
?
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Re: Standoffs for mounting the board
Also, I will have the help of a drill press and an experienced operator.
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Standoffs for mounting the board
I bought a thick walled aluminum enclosure for my bitx. ?Rather than drill holes in the bottom of the enclosure and have the standoffs be secured by a nut or screw from the bottom, ?I am thinking of tapping the enclosure and simply screwing the standoffs into the tapped holes. ?I have never tapped anything before, so are there any issues I should be aware of?
Also, I have decided to purchase new standoffs so that I am positive that the tap and the standoff are using the same thread size. ?Are there any recomended standoff sizes for the radio? ?I have seen thread sizes in M2, M2.5, and M3. ?Are any one of these preferable?
Thanks.
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Re: add yourself to the new BITX operators map
OK, that was a bit off base. ?Looking again, map doesn't show anything more than a pin till highlighted with the mouse.
I don't care if we standardize on just a call or call+name or whatever.
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On Fri, Jun 9, 2017 at 04:38 pm, Jerry Gaffke wrote:
If you're in antartica and there's lots of room around your call, then probably ok
to have more than just your call on the map pin. ?But if there's 20 other pins on top of yours,
best to stick with just a call. ?
?
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Re: add yourself to the new BITX operators map
Yup, great idea!
Thanks for setting up the map.
If you're in antartica and there's lots of room around your call, then probably ok
to have more than just your call on the map pin. ?But if there's 20 other pins on top of yours,
best to stick with just a call. ?
Fine with me if you put any info whatsoever in the pop up tag.
A first name would be friendly.
Maybe a URL to a website fully describing all the stuff you have done to your rig.
But I'm not going to update the map every time I try a new antenna or PA supply voltage.
Though might give some indication if I ever get one of these: ?Just so you know, my rig has been modded with a ?custom front panel. ?Back panel too.
If for some obscure reason you need to know my license class, you'll have to check in with fcc.gov
I'd prefer an uncluttered basic map.
Maybe there is something meaningful we could do with the colors,
but I can't think of what that would be.
Color preference, perhaps.
I like blue.?
Jerry, KE7ER ? ?Flora OR
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On Fri, Jun 9, 2017 at 03:22 pm, Craig Thibodeaux wrote:
1. Call for what unique ID’s others would like to see
?
Stock
Modded (how)
Antenna (details)
Lic Class
Region is already shown on map (after thinking about it)
First Name?
?????
?
2. ?After agreeing to a list, then decide how to implement, within limits of Pins, Title box, Description Box
?
3. After this map fills up…..uniformity will make it usable, requiring agreeing on abbreviations, color codes, placement, order, etc…..
?
Again, Great idea Doug
?
?
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The problem is that he uses a different encoder where I use a eBay encoder
On 9 Jun. 2017 4:55 pm, "Ryan Flowers" < geocrasher@...> wrote: With the raduino you will have to enable USB and it'll switch the VFO to +12mhz offset instead of -12mhz offset. I did this on my BITX40 though I use the QRP Labs VFO. The principal is the same. You do have to remove C91 and C92 to make it work:
--
Ryan Flowers W7RLF
?
?<-- Learn how to go digital on the BITX40
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Re: Making PSK31 Contacts
I agree with Clark. Increase the size of your heat-sink,
especially if you are primarily using digital modes
It is easy to do. Use a computer cpu sink, or go to some place
like Tractor Supply and buy a strip of 3 in x 1/4 in aluminum
and cut your own.
Sometimes you can find them surplus; the best ones I have found
were originally designed for voltage power converters. They have a lot
of dissipation area in a small footprint. Another good place to look is
in linear power supplies, especially the strips used for the amperage
bypass transistors. Sometimes one can also find good ones in old
stereo amplifiers as well (less so in old TV sets).
Always remember to isolate the IRF510 as the tab is "hot".
john
AD5YE
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Re: Other 2 line displays
Phil:
Regarding displays, what you are looking for essentially is a
HD44780 compatible 2x16 lcd display. Usually they are either
back-lit or not. They can have a parallel or serial interface.
You need a parallel interface, 2 lines x16 characters, 5x7 matrix display, with back light.
They come in many colors, mainly green, blue, red, or some variation
of these colors. One of the usual generic part numbers is 1602.
Lots of them now-a-days are pushing serial interface. This may be built-in or add-on.
They will not work with the Raduino, though the serial add-on board is easily removed. The
built-in serial interface is not compatible.
They are available all over e-bay, and cost about $US2.00 each. The only reason one
might want another is to change the color, I guess. Note that something like a 2x20 or 4x20 display
(HD44780 compatible) will also work; they will have more spaces or lines than you need; that's all.
john
AD5YE
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Re: Making PSK31 Contacts
On Jun 9, 2017, at 1:09 PM, Jeff < jeff@...> wrote:
Clark thanks for the advice. I kinda already did that with the original heatsink. I modified it to fit flat to the chassis and have the transistor mounting screw thru the chassis and into the heatsink. I was surprised that the heatsink got warm as well. I expected the chassis to absorb most of the heat. If it gets too warm my thought was to replace it with a microprocessor heatsink and small fan
That is an awfully small heatsink for the power being dissipated. ?I would go with something at least 2” x 2” x 1/2”.
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Re: add yourself to the new BITX operators map
Is everyone else seeing two posts for every reply of mine?
or is that just a ‘feature’ since it is me?
If everyone is seeing two, how can I stop this?
Craig
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On Jun 9, 2017, at 6:22 PM, Craig Thibodeaux < km4yec@...> wrote:
Doug,?
I would suggest:?
1. Call for what unique ID’s others would like to see
Stock Modded (how) Antenna (details) Lic Class Region is already shown on map (after thinking about it) First Name? ?????
2. ?After agreeing to a list, then decide how to implement, within limits of Pins, Title box, Description Box
3. After this map fills up…..uniformity will make it usable, requiring agreeing on abbreviations, color codes, placement, order, etc…..
Again, Great idea Doug
Craig KM4YEC
Now I know why I hung multiple monitors up on the wall.
Both good points Craig.? A few general notes to the group: As to needing to sign in, I have the editing permissions as open as possible.? If anyone wants on the map and can not do it for any reason email me at KD9CYF@... with add to map in the subject or reply to this topic with your call and address and I will add you manually. I like the idea of differentiating stations with colors or different icons or both.? What do you guys like?? Craig has some good one already. I am going to try to keep the map clean and consistent so I may edit some of the entries manually if I can figure out what the operator's intention was.? However, there are a few points already that have no call or address and are therefore useless to the group.? I am going to delete those.? Again, if you need help or want me to add you manually just say so. Thanks to everyone that has already added themselves.? I hope this turns into something useful. #map
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Re: add yourself to the new BITX operators map
Doug,?
I would suggest:?
1. Call for what unique ID’s others would like to see
Stock Modded (how) Antenna (details) Lic Class Region is already shown on map (after thinking about it) First Name? ?????
2. ?After agreeing to a list, then decide how to implement, within limits of Pins, Title box, Description Box
3. After this map fills up…..uniformity will make it usable, requiring agreeing on abbreviations, color codes, placement, order, etc…..
Again, Great idea Doug
Craig KM4YEC
Now I know why I hung multiple monitors up on the wall.
toggle quoted message
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Both good points Craig.? A few general notes to the group: As to needing to sign in, I have the editing permissions as open as possible.? If anyone wants on the map and can not do it for any reason email me at KD9CYF@... with add to map in the subject or reply to this topic with your call and address and I will add you manually. I like the idea of differentiating stations with colors or different icons or both.? What do you guys like?? Craig has some good one already. I am going to try to keep the map clean and consistent so I may edit some of the entries manually if I can figure out what the operator's intention was.? However, there are a few points already that have no call or address and are therefore useless to the group.? I am going to delete those.? Again, if you need help or want me to add you manually just say so. Thanks to everyone that has already added themselves.? I hope this turns into something useful. #map
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Re: add yourself to the new BITX operators map
Both good points Craig.? A few general notes to the group: As to needing to sign in, I have the editing permissions as open as possible.? If anyone wants on the map and can not do it for any reason email me at KD9CYF@... with add to map in the subject or reply to this topic with your call and address and I will add you manually. I like the idea of differentiating stations with colors or different icons or both.? What do you guys like?? Craig has some good one already. I am going to try to keep the map clean and consistent so I may edit some of the entries manually if I can figure out what the operator's intention was.? However, there are a few points already that have no call or address and are therefore useless to the group.? I am going to delete those.? Again, if you need help or want me to add you manually just say so. Thanks to everyone that has already added themselves.? I hope this turns into something useful. #map
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Re: add yourself to the new BITX operators map
Great idea Doug,?
1. need to sign in to Google first to add address.
2. to use as a differentiator of stations….some ideas
use the color feature to show something different about your station? Stock BitX40 vs Mods vs 12v or 24v on PA, ?Region, Lic Class (make a difference on contact freq), or anything else that would be nice to know about each other. ?
also, the identifier line could include First Name, or 1 or two other unique ID’s….
thinking to make it a pictorial database
Craig KM4YEC
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Seeing the topics for regional operator lists got me thinking.? If words are good, pictures are better.? I set up a google map that you can add yourself too to help visualize where everyone is located.? I was going to add people that responded to the other topics but out of respect for privacy (and my laziness) this should be entirely opt in only.? The map is only accessible with the link below.? The interface is reasonably intuitive but I will do my best to explain how to add yourself.
go to type your address in the search bar on the top of the map (the box with the magnifying glass to the right)
hit enter or click the magnifying glass
verify the location displayed
click add to map at the bottom of the box that pops up
now click the pencil/edit icon at the bottom right of the box
change the highlighted address to your call sign and click save at the bottom left of the box
you can also add more information to your spot if you choose to
bookmark the link and check back as more people add themselves
I am making this sound much more complicated than it is.? If anyone can describe the process better please do.
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Jeff
Raj vu2zap
Craig Thibodeaux