The Tekpower TP3005T looks like an excellent bench supply. A linear power supply using a tapped transformer, so likely cleaner than most switchers, still reasonably efficient. Though at $80, kind of spendy for somebody who spent considerably less on their Bitx40. Here's a cheaper one, this one is a switcher so is probably (but not necessarily if they did it right) noisier: ? ?? Lots and lots of cheap switching power supplies that only have one knob to set the output voltage. Here's a nice 30 Amp switching power supply for use with a 100 Watt transceiver:? ? ?? So for the same price as the Tekpower, you can have 6 times the current out. You can set the output voltage to anything between 4 and 16 Volts. The meter can monitor either voltage out, or output current. Seems to be about as RF quiet as any linear power supply. But does NOT allow you to set the maximum current like the Tekpower,? it's always ready and waiting?to give your project 30 Amps. The Tekpower has that extra knob, allows you to set the maximum current. If you are first checking out a uBitx on receive, you could set the maximum current to perhaps 300ma. So the Tekpower will deliver 12v to the uBitx (or whatever voltage you set) up to 300ma, If the uBitx has a short somewhere, the Tekpower then reduces its output voltage until the current is 300ma, perhaps down to a voltage of nearly zero if that's what it takes.? No burned traces, no smoke. To check out a zener diode, just put it across the output terminals of the Tekpower and set the max current to 10ma. (I'm assuming that you can accurately set the current low enough.? May not be the case.) The way you set the max current is to put a short across the output terminals, then twiddle the knob for the desired current. Weird that there are not more supplies that provide this extra knob to set the maximum current, the additional electronics required is minimal. There is another form of current limiting that you might want to be aware of:? Foldback current limiting. If your project exceeds the maximum set current, the power supply shuts down entirely until reset. Pretty much like a circuit breaker. This is not as common (or useful) in a bench supply as the simple current limiting of the Tekpower supply. ? If you want cheap, I suggest going to a second hand store and buy a 12v desktop "brick" style supply good for 3 to 5 Amps. If it's too noisy during receive (compare it to running from a 12v battery) buy another and use the noisy one for other projects. But these bricks will not have adjustable max output current like the Tekpower. Jerry, KE7ER
On Sat, Nov 24, 2018 at 07:44 AM, KD8CGH wrote:
Supplies made for amateur radio are usually quiet. You don't need instruments - if you hear the supply in your transceiver it's too noisy.
I have two 30 amp linear supplies, but my precocious desktop space goes to a Samlex SEC123 switching supply. I use a fused distribution box from a Sotabeam kit.
If you are interested in QRP, building kits and different voltages you might consider a bench power supply. I use a Tekpower TP3005T Variable Linear DC Power Supply, 0-30V @ 0-5A which provides current limiting as well as voltage regulation.
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Re: To shield or not to shield, that is the question.
Hi,
Shielding also protects the receiver circuits from external "crud". So much for the QRP argument. *All of my radios live in steel or aluminum, even the one with pretty plastic panels on the outside. Those are for cosmetics only. Plastic can shield against water:) Stay indoors and it won't get wet.
73,
Bill KU8H
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On 11/24/18 11:25 AM, Jack Purdum via Groups.Io wrote: If you don't care, a metal case is probably best so you can shield it. I'm doing one for my personal use that has a metal surround, but plastic end panels (easier to cut). However, the "display model" that we will use to show it off will have an acrylic U-shaped cover with an acrylic front panel and metal back panel (e.g., antenna, power, speaker connections). One of our book projects is an antenna tuner with "instant" readout of SWR on a TFT color display, which originally was in a plastic case. That project benefited from shielding, but we were testing it with 100W. We retrofitted copper foil shielding inside the case and that worked well. So, pick what looks good to you and if you think there's an RF issue, line the case with foil.
Jack, W8TEE
On Saturday, November 24, 2018, 11:09:46 AM EST, Lee <mr.olson@...> wrote:
Some have built in metal boxes, some use plastic boxes, and some put metal shielding inside the plastic boxes.? Is it a ,should do, must do, or doesn't really matter at these low power levels.?? Can you also explain why you made your choice?? Thinking about options for for my JackAl add-on new radio build.
--
Lee - N9LO /"I Void Warranties"/
//
--
bark less - wag more
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STREAM of solar wind is approaching Earth and experts fear it could hit us as early as November 26
?STREAM of solar wind is approaching Earth and experts fear it could hit us as early as November 26
On Sat, Nov 24, 2018, 11:26 Jack Purdum via Groups.Io <jjpurdum= [email protected]> wrote:
If you don't care, a metal case is probably best so you can shield it. I'm doing one for my personal use that has a metal surround, but plastic end panels (easier to cut). However, the "display model" that we will use to show it off will have an acrylic U-shaped cover with an acrylic front panel and metal back panel (e.g., antenna, power, speaker connections). One of our book projects is an antenna tuner with "instant" readout of SWR on a TFT color display, which originally was in a plastic case. That project benefited from shielding, but we were testing it with 100W. We retrofitted copper foil shielding inside the case and that worked well. So, pick what looks good to you and if you think there's an RF issue, line the case with foil.
Jack, W8TEE
On Saturday, November 24, 2018, 11:09:46 AM EST, Lee < mr.olson@...> wrote:
Some have built in metal boxes, some use plastic boxes, and some put metal shielding inside the plastic boxes.? Is it a ,should do, must do, or doesn't really matter at these low power levels.?? Can you also explain why you made your choice?? Thinking about options for for my JackAl add-on new radio build. -- Lee - N9LO? "I Void Warranties"
?
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Re: To shield or not to shield, that is the question.
If you don't care, a metal case is probably best so you can shield it. I'm doing one for my personal use that has a metal surround, but plastic end panels (easier to cut). However, the "display model" that we will use to show it off will have an acrylic U-shaped cover with an acrylic front panel and metal back panel (e.g., antenna, power, speaker connections). One of our book projects is an antenna tuner with "instant" readout of SWR on a TFT color display, which originally was in a plastic case. That project benefited from shielding, but we were testing it with 100W. We retrofitted copper foil shielding inside the case and that worked well. So, pick what looks good to you and if you think there's an RF issue, line the case with foil.
Jack, W8TEE
On Saturday, November 24, 2018, 11:09:46 AM EST, Lee <mr.olson@...> wrote:
Some have built in metal boxes, some use plastic boxes, and some put metal shielding inside the plastic boxes.? Is it a ,should do, must do, or doesn't really matter at these low power levels.?? Can you also explain why you made your choice?? Thinking about options for for my JackAl add-on new radio build. -- Lee - N9LO? "I Void Warranties"
?
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Re: 160 metres and the uBITX
This was my scope capture with the CW key pressed.
?
John, K5GT
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Barry, Evan,
Thanks... It is good to know that microphonics an happen to a working board.? Now I can chase other things that may be part of the distorted audio and low sensitivity!? ...Then on to tackle the TX problems.
TNX - Woody? KZ4AK
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On 11/24/2018 3:36, barry halterman wrote: Woody, I have issues with microphonics too, but with my ubitx on a decent antenna they get drowned out from other background (band) noise. I only notice them if I am on a dummy load or have the antenna disconnected.
73
K3BO
Bar
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Re: To shield or not to shield, that is the question.
Some have built in metal boxes, some use plastic boxes, and some put metal shielding inside the plastic boxes.? Is it a ,should do, must do, or doesn't really matter at these low power levels.?? Can you also explain why you made your choice?? Thinking about options for for my JackAl add-on new radio build.
--
Lee - N9LO? "I Void Warranties"
?
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Hi all,
So far hadn't touched my uBitX v3 for a while. This week I started building the AGC-kit I had ordered a while ago and added another 3.5mm audio connector to make a separate connection for a paddle.
Have not used CW as of yet, first have to practice? bit more ;) So far my operation have been limited to the higher bands (20+) and FT8.
Now that I was playing around and recently also obtained a GP5-SSB I was able to listen to my signal using a dummy load. Listening I discovered that when the key or paddle is not pressed you hear a faint tone (keypress is much louder) Is this because I am so close to my uBitX and is it the zero beat of the 700Hz? that I am hearing?
John
K5GT
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To shield or not to shield, that is the question.
Some have built in metal boxes, some use plastic boxes, and some put metal shielding inside the plastic boxes.? Is it a ,should do, must do, or doesn't really matter at these low power levels.?? Can you also explain why you made your choice?? Thinking about options for for my JackAl add-on new radio build. -- Lee - N9LO? "I Void Warranties"
?
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Looking at the output of my uBITX on 160m on a spectrum analyser, you don't want to go there!
However, a simple external low pass filter makes all the difference.
Attached is the circuit of a LPF that I built, along with before and after analyser screen shots of the output of my uBITX.
73 de Barry, G4BUD
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Supplies made for amateur radio are usually quiet. You don't need instruments - if you hear the supply in your transceiver it's too noisy.
I have two 30 amp linear supplies, but my precocious desktop space goes to a Samlex SEC123 switching supply. I use a fused distribution box from a Sotabeam kit.
If you are interested in QRP, building kits and different voltages you might consider a bench power supply. I use a Tekpower TP3005T Variable Linear DC Power Supply, 0-30V @ 0-5A which provides current limiting as well as voltage regulation.
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Looking on the components side of the Bitx 40 board right side about 1/2 way, I see a 2 prong connector labeled TUNING. My instruction sheet from HF Signals shows nothing, no connections. anyone have any idea if this is connected and where to?
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Anyone have a Kees AGC board FS?
If you bought one and decided not to use it, I'd like to fine one.?
?
Thanks
John K5MO
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my rad had a bad usb port on it. turns out i had to nudge a small tang of metal inside the connector on the nano. if your cable goes vall the way in the disregard this post.
Dave n4lkn
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Re: Bitx40 Power Supply - stackeing 4 2032 Lithium coin batterieis?
Unfortunately, that battery is only rated for?235 mAh.? On a BITX40, it would have a short, but happy, life.
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Yes, I had microphonic issues with my board.? After removing and replacing the boards multiple times for other upgrades or issues?it went away.? Still not sure if it was flexing the main board or inserting and removing the Raduino multiple times that fixed the problem. I would guess that it was the Raduino to uBitx connection, as that was the most worked.? May have had some dirt on one of the pins.
Evan AC9TU
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Bill,
Thanks for the tip! I've checked out but it never occurred to me to use it in that manner. I may have to try that.
?
73,
?
Jared KN4IYL
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Woody, I have issues with microphonics too, but with my ubitx on a decent antenna they get drowned out from other background (band) noise. I only notice them if I am on a dummy load or have the antenna disconnected. 73 K3BO Barry
On Nov 23, 2018 9:18 PM, "Woody" < mailme@...> wrote:
Mike,
Interesting link but as you suggested, the most likely would be RF
intrusion.?? Was transmitting (into dummy load) when failed. ?
Still wonder why, since it was the "nth" time the xmit was on.?
Wire movement? freq different?? Too many variables...? TX was
acting weird at that point. 10 MHz and up was pretty much like
others have experienced.? At lower freqs, the power dropped to 1-2
watts and the current increased almost an amp.?
In addition to my RX problems need to investigate the (above)
unusual RF power / current draw (was starting to troubleshoot when
lost nano).?? Wonder if high SWR on lower freqs affected current
and generated more stray RF ????
Will add ferite to lead wires before next xmit and cross fingers.
--
To All -? CURIOUS:??
Is the board microphonic for anyone else?? With the volume up
(slight background tone) tapping or lightly dragging a plastic
diddle stick across the components can be plainly heard from the
speaker.
TNX,
Woody
----------------------------------------
On 11/24/2018 0:33, Mike Woods wrote:
Woody
It's pretty easy to kill a nano.?? See
And it may have been RF, putting the connector on one pin out of
line, and a whole bunch of other ways ...
Mike ZL1AXG
On 24/11/18 1:04 PM, Woody wrote:
Solved...
Thanks to a comment from Jim, one problem solved.?? Idiot me did
not adjust the display contrast before deciding the kit had an
assembly problem.?? A tweek of the contrast pot, and there where
characters!
Still wonder why the original nano died...?? At least I can now
proceed to trouble shoot the main ubitx board.
Woody??? KZ4AK
--------------------------
On 11/23/2018 20:05, Woody wrote:
Will welcome any suggestions...
History:
Using UBITX_CEC_V1.080_16P.hex. Original Raduino died during
transmitter testing.??? Display: Top row all filled
characters, Bottom row no characters.? This is what is
displayed while waiting for boot to complete with working
unit...? Tried to reload firmware...
UBITX Manager: Connects OK (38,400 baud), but READ UBITX
returns error - [6:31] ERROR RECEIVE LENGTH = 0/1027
Reset does not return error.?? After "reset ubitx", reconnect
and tried to upload original btx file - reported success...
Then...
Using XLOADER, tried uploading UBITX_CEC_V1.080_16P.hex again
(57,600 baud, at 38,400 - can't open port)? ---? Tries to
upload, but stuck at "uploading...", never completes.
So...? Ordered new Raduino kit from W0EB.? Different problem:
Display lights, no characters either row.
----
Memory manager connects, Read ubitx seems to work.? Got data
and the info: [6:57 PM] Check sum compare 57:57
[6:57 PM] READ SAMPLE :
02,D2,DD,FF,FF,00,00,00,00,B2,0E,B7,00,00,00,00,00,10,93,6B,00,C8,09,6F,00,00,00,00,00,0E,00,00,
Memory Manager
Reset seems to work.
Loading btx from file reports "success".
Using Xloader, loaded UBITX_CEC_V1.080_16P.hex,? apparently
successful.
Lit, but still blank display.
--------------------------------------------------------------------------------------------------------
THEN... Put the new arduino nano (from W0EB) in the original
Raduino board.?? Seems to work!
--------------------------------------------------------------------------------------------------------
Apparently I have two issues.? A bad Nano in original, and
something wrong with my new kit.
I have carefully examined all solder joints using 10x eye loop
and 20x stereo microscope.? No bridging, joints look OK.
Two questions:
1) Any suggestions about why the original Nano died?? Don't
want a repeat!
2) What could be causing the lit but blank display on the new
kit?
Thanks for any suggestions.
Woody,? KZ4AK
--
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Hi,
Are you familiar with WebSDR? Those are SDR receive stations that are shared over the web. You can find them in various places covering various parts of the spectrum. Multiple users can use each one of them at the same time on different frequencies and different modes. If you don't know about them you should look into them and play with them a little.
Some key features are:
They are not in the same room as your transmitter! Does that ring any bells? :)
You get some idea how well your transmitter and antenna are getting out various locations. When you look those up on the WebSDR site they tell your right where they are:)
They are not in the same location as your industrial QRM. If industrial noise is giving you trouble at your home location you might consider using one of these receivers at it's quieter remote location and using your transmitter at your home to work other stations you hear on the Web SDR receiver. Choose wisely. If your are using a Web based SDR that is shared from Timbuktu in central Africa from San Diego on 80 meter CW you will probably not work anything that station can hear even though you can hear it. Choose a station that is in your own region so that other hams you hear on the remote receiver have a chance of hearing your transmitter:) There may be some pleasant surprises.
73,
Bill KU8H
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On 11/23/18 6:46 PM, KN4IYL wrote: Bill, you caught me. The receiver is about a foot away. Lesson learned, and thanks for everybody's input.
--
bark less - wag more
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Re: Possibly the last person to get a uBitx on the air.
John
We are doing a group build of 23 rigs, many more behind you.
Check out 2 versions of nd6t agc, to cure that.
Yes cw via one arduino pin, you can get used to it. I may try w0eb firmware and hardware solution someday.
Dynamic mic, using a single transistor stage, solutions are out there on the web, and a very recent qst.?
I suggest using the stock firmware, then reading about 2 nice alternatives,? not in a hurry to decide.
Our club is using the fix with an extra 45mhz xtal and a daughter board with relays to cure the spurs.
Enjoy your ubitx ride while you sort it all out.
Curt
Central MD
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N2LO
Lee
Bob Benedict, KD8CGH
