Re: Standoffs for mounting the board
Using the drill press for tapping is an excellent way to go. ?Considering the size of the tap and the type and thickness of material, you should easily be able fully tap the hole by hand. ?Cutting oil is a necessity. ?Power tapping is tricky!
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Re: Standoffs for mounting the board
For your reference, .
I'm not sure of the wisdom of actually using the drill press under power to complete the tap. You really don't want to go much faster than you could by hand. Not sure how thick the box metal is, but a little cutting oil (or any oil if you don't have cutting oil) saves a lot of wear and tear on both the box and the tap.
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John - WA2FZW
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I'm not certain that I reversed the polarity - I just assumed that that was the case as I do have a track record, however I thought I had been quite careful. I'll trace the leads through again when I get some time - I'll also look for any solder bridges etc on the board
thanks for your help - fingers grossed the whole board isn't fried!
Matt 2E1HNK
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Re: Other 2 line displays
Thanks for the info, I find some colours easier to look at, age I suppose plus other problems. Now I know what to look for.
Many thanks.
Phil - G7BZD
On Sat, Jun 10, 2017 at 3:57 AM, John Smith via Groups.Io <johnlinux77@...> wrote: 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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Re: Standoffs for mounting the board
The important things to keep in mind when tapping are;
1.? Drill the correct size hole for the size of the thread.
2.? Keep the tap perpendicular to the surface. Here the drill press will help you out. Simply chuck the tap firmly but loosely in the drill press and use it to align the tap while turning the spindle by hand to start the tap. After the first 3 or 4 turns then switch to a tap handle to finish the threads. If you have some experience you can use the spindle under power to do the threads. I do it often.
3.? M3 is a common size for this chore using that size will leave you with a tap that can be used to chase threads and make repairs to other threads. 6 mm, 9 mm, 12 mm and 24 mm are all very useful with 6 mm being the most useful.
PJH, N7PXY
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Re: add yourself to the new BITX operators map
Great idea! I'm in!
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John - WA2FZW
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Putting Leftover Holiday Items to Work
Nothing quite like Trader Joes's to satisfy your electronic needs.?
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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
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?<-- 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
toggle quoted message
Show quoted text
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
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?<-- Learn how to go digital on the BITX40
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Matt Carus
Jeff
Raj vu2zap
Craig Thibodeaux