Re: Power supply from a repurposed pc PSU
Neat set up there with the banana connectors.
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Power supply from a repurposed pc PSU
I needed a regulated power supply to run my mBitX and a couple arduino kits, but didnt feel like shelling out a hunderd + bucks. So I modified an ATX power supply from a dead pc. I get 3v, 5v, and 12 volts, made from parts on hand. I also salcaged a bunch og parts from the dead pc, including a few torroids from another power supply. 
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Re: 2.8 Mhz parasitic signal on 15 and 20m
#ubitx
the difference is constant, both when tuning and when changing band
it's a V3
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I'm intersted in a kit as well (ZL2TUD)
I have been using OMRON? G2RL-1-E-CF relays for filter /antenna selection they are good to over 1kW CW and are relatively cheap differnt coil voltages are available
This is backed up by W6PQL who has done lots of testing and uses them up to 70cm.
The inards of these relays is very close to the relay corners and an inadvertant touch with the soldering iron will render the relay useless.
No relay will handle huge RF currents while switching so tuning has to be done at reduced power
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units EPROM memory allocation map?
Hi,
Is there a map of the ubitx EPROM memory somewhere that shows locations are allocated vs those that are "free"? As I am working on the 5" Nextion UX, it would be useful to store some values (e.g. offsets from beginning of band for the band scan function) so that the user would not have to enter them on every boot. Using ubitx Datamanager, there does appear to be lots of zeros....
Mark
AJ6CU
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SolderSmoke Podcast: Boatanchots, Antuinos, and SDR too
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WHICH MODEL IS IT FOR?
SHEP AA7MH
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Re: #v5 finally got my V5 together and working, PA bias question
#v5
#ubitx
#pabias
Hi Dennis,
This seems perfectly normal to me.? My v3 (as delivered without and changes to the bias) on CW drew from 2A on 80m to less than 1A on 10m, on SSB with a microphone and a loud "hello" it should require similar current draw.
Did you read somewhere that it is supposed just draw 1A?? This wouldn't made sense.? The rig draws about half and amp on idle without speaking into the mic.? So that figure would make just half an amp over that for transmission.? 0.5A x 12V makes 6W consumption and at about 2/3 efficiency that makes just 4W out -- for sure the radio can do more than that on some bands.
73,
Mark
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Re: 2.8 Mhz parasitic signal on 15 and 20m
#ubitx
Questions!
1: Which uBitx model is this ?
2: Is the carrier to spur frequency difference constant in separation or does it increase and decrease as you tune ?
Raj
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Show quoted text
At 22/06/2019, you wrote: When I use SSB on 20, 18 and 15m, I get a strong signal (20db below the main signal) 2.8Mhz left and right of the tx frequency, as if the carrier is being amplitude modulated with 2.8 Mhz.
I already tried disabling the PA power and measuring the signal at different points before the PA, but this signal isn't there, not even directly at the power MOSFETs. When I enable the PA, I can't measure low power signals on the PCB anymore.
On all other bands, this singnal isn't present. In CW mode, the signal isn't there on any band.
Has anyone observed something similar? I'm completely at a loss. Spectrum analyzer screenshots will follow as soon as I get everything set up again.
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Re: 2.8 Mhz parasitic signal on 15 and 20m
#ubitx
Which version of ubitx do you use?
When I use SSB on 20, 18 and 15m, I get a strong signal (20db below the main signal) 2.8Mhz left and right of the tx frequency, as if the carrier is being amplitude modulated with 2.8 Mhz.
I already tried disabling the PA power and measuring the signal at different points before the PA, but this signal isn't there, not even directly at the power MOSFETs. When I enable the PA, I can't measure low power signals on the PCB anymore.
On all other bands, this singnal isn't present. In CW mode, the signal isn't there on any band.
Has anyone observed something similar? I'm completely at a loss. Spectrum analyzer screenshots will follow as soon as I get everything set up again.
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2.8 Mhz parasitic signal on 15 and 20m
#ubitx
When I use SSB on 20, 18 and 15m, I get a strong signal (20db below the main signal) 2.8Mhz left and right of the tx frequency, as if the carrier is being amplitude modulated with 2.8 Mhz.
I already tried disabling the PA power and measuring the signal at different points before the PA, but this signal isn't there, not even directly at the power MOSFETs. When I enable the PA, I can't measure low power signals on the PCB anymore.
On all other bands, this singnal isn't present. In CW mode, the signal isn't there on any band.
Has anyone observed something similar? I'm completely at a loss. Spectrum analyzer screenshots will follow as soon as I get everything set up again.
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Re: #v5 finally got my V5 together and working, PA bias question
#v5
#ubitx
#pabias
my setup is as follows, i have a bench power supply set at 12v usually flicks up too 12.1, antenna is plugged into a dummy load
I am seeing the increased draw on my bench power supply. Is this over current going to damage my bitx, should I go through the tune up steps? Any one?
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?Yes, you need to check the connectors for the rig you are using.
?Easier for them to simply use one set of connectors as there is less demand for the ones for the BIT40 now. ?I will be making one for a BITX20 also,as I have a bare board kit for 20, 40 or whatever band I? choose
I? checked, and considering the orange goes to 12 v from pin 2, that plug in is correct .? Yes, it is necessary for the correct band bitx software to be loaded by HFSIGNALS . They most likely do these one at a time custom these days.? If the software? isn't correct,? there are things necessary to learn,? exciting stuff,? already on line,? and with help ,? you could be successful.??
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I¡¯m planning to build a version of the K3NG auto tuner as well. I am looking at using a Sainsmart 16 relay module (Amazon $14.99) for the L&C and a 2 relay version for the hi/lo and antenna switch. N9KR used these modules. (Search YouTube for N9KR). Also going unbalanced. Great info on the SWR detectors. I plan to build in a noise bridge as well for no transmit tuning.?
--
John Faivre?WA9SGD
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And , after telling you all of this,? I'm going to do additional stuff to my original raduino equipped BITX40. I? want it to be extremely low powered on rx. So I'll add a non raduino External VFO like this?
http://bitxhacks.blogspot.com/2016/11/an-vfo-for-bitx40.html?m=1 This is one of the BITX40 hacks listed at HFSIGNALS.COM and I am thinking that the current on rx will go down to 1/2 amp or less!?
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Ashhar this issue comes up often and can be confusing for new users.? Any chance of revising the BITX40 wire up page to show how to use the Raduino with right angle pins with the BITX40 and note that the firmware needs to be changed?? Maybe even include a note in the box?
--
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The rad¨¬ino your showing is a uBITX raduino. To change it to a BITX40 raduino,? first part is fairly easy.? You remove all but 5 pins on the 16 pin header. Or, just simply plug in the five pin connector as shown in this link.?
/g/BITX20/topic/17656380?p=Created,,,20,1,0,0::,,,0,0,0,17656380
?Carefully,? as you may want to put them back some day. (If you remove them, I? wouldn't ) And, I? gave you a video link showing pre date ubitx differences . Can you tell which pins of the header need to be removed?? (If you remove them ) This isn't typical of a starting experience.? In addition to that the bitx40 software would need to be loaded.? But, it may be already there.? A is a simplified method available.? Not sure if Ashar will be able to help you.? Once you've removed all but five pins of the 16 pin header,? a five pin plug with colored wires is connected by plugging it into the pins left on the raduino . Red is not 12v. Refer to the 40BITX instructions here.? That said, I? wouldn't remove the pins, just tape the "extra" ones.? I? suspect the BITX40 software is pre loaded for each BITX40. A custom operation as few BITX40 are sold these days,? and all raduinos are set up for uBITX boards.??
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I? checked, and considering the orange goes to 12 v from pin 2, that plug in is correct .? Yes, it is necessary for the correct band bitx software to be loaded by HFSIGNALS . They most likely do these one at a time custom these days.? If the software? isn't correct,? there are things necessary to learn,? exciting stuff,? already on line,? and with help ,? you could be successful.??
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Hello Eric, ??????????????? That atu design of yours is Just what ive been looking for to use with my ubitx.I will let you know how the build goes and hopefully send you some pics of the finished atu.regards Dave G0AYD.
There is an article about a standalone silent tuning QRP ATU design with a schematic at the link below.
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Nice unit. ?I added the page to my collection of articles for possible future
Won't look as nice maybe, but I like utility over looks.but it
?I have an auto ATU, likes, it seems, at least 5 to 10 watts to operate. ?Thanks for the article
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Jim
Raj vu2zap
Michael Shreeve