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- BITX20
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Re: Bitx 20 microphone problem
I would suggest that you verify that the BITX20 will go into TX by jumpering the pins on the mic/PTT jack on the radio temporarily.? If that works, then the problem is in the mic.? If it does not go into TX then you have an issue in the radio.
Looking at the schematic, I see that the PTT line is keying K1.? If the problem is in the radio, then I would first trace the wires and be sure the jumper did not get disconnected in the move.? If the wiring is OK, then you will probably need to change out K1.? This all assumes that the Raduino is not used in the PTT line.? There are mods that added CW and other functions through the Nano on the Raduino add on from the original. I do not have either a BITX20 nor a 40, so the above are just suggestions.? Details of the rig, including any modifications done would be needed to provide any other suggestions.? Since it worked before, was put into storage, and now does not work, my best guess is the wiring was dislodged. 73 Evan AC9TU? |
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Re: Test equipment recommendations
If your interest aligns with this:
The NanoVNA is a nice piece of equipment for not a lot of money. I have an H model. It does have a steep learning curve which would be true of any VNA. Build yourself a wire antenna. Make it cheap, use speaker wire from the hardware store. Download the free copy of Eznec and model the antenna in it. Use the Nano to tune it and compare it to the model. When your done, you'd have a good fundamental? understanding of antennas, a beginning knowledge of antenna analysis,? and you'll know the vna well enough to tackle other vna work like evaluating baluns and circuit impedences. There's plenty of resources on the internet to help you figure it out. |
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Bitx 20 microphone problem
Hi I purchased a built bitx20 from ebay a couple of years ago, which I have been using as a portable station on holidays. The microphone that was supplied with it was an old CB hand microphone. This has worked well but when I got the bitx out of storage to use this summer the microphone will not key the radio. The radio still receives as usual but will not key to transmit. I have dug out one of my old CB radio's ans the microphone will key this radio. Does anyone have any idea what could be going on with the bitx. None of the microphones I have to hand will work with it. Any ideas suggestions would be much appreciated.
Thanks Nigel G7luo |
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Re: Checking SWR with BITx40
you can find an online tone generator and push that into the mic or just hold mic to the PC's speaker. - f On Mon, May 18, 2020 at 2:03 PM Vic WA4THR via <vhklein=[email protected]> wrote: If you update the software to Allard's sketch he also has a simple mod to add CW capability for the BitX40. Then you can key the rig with a steady carrier to allow checking SWR or use an antenna tuner. You could also try feeding a steady tone into the microphone from your phone or something to get a reading you can check. |
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Re: Checking SWR with BITx40
If you update the software to Allard's sketch he also has a simple mod to add CW capability for the BitX40. Then you can key the rig with a steady carrier to allow checking SWR or use an antenna tuner. You could also try feeding a steady tone into the microphone from your phone or something to get a reading you can check.
=Vic= |
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Value of the 45mhz filter?
³Ò¨¦°ù²¹°ù»å
Hello
Request information about filter 45mhz What is the bandwidth of the (of) 45mhz filters. + /- 7.5 khz or +/- 15khz. thanks It's for future modification for spurs https://ubitx.net/tag/spurs/ It's write: "The filter is a 45MHz 15Khz type filter identical to the existing roofing filter in the ?BITx and replacing R27 in the original circuit" I am making my one:? If some one have 2 to sell (I am in france) or where to find it. cdt |
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Re: Checking SWR with BITx40
This is the nature of SSB.? You can't get an accurate read on SSB because it's comes from removing one sideband and carrier from Amplitude Modulation.? So it modulates the amplitude (power) of the signal based on the input.?? You should get a antenna analyzer.? It will give you a picture of the whole range of the antenna and not just one specific frequency.? The Nano VNA is rediculous cheap.? Less than $25 now.?? On Sun, May 17, 2020, 22:46 Scott Skroch <sskroch@...> wrote:
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Checking SWR with BITx40
Scott Skroch
My son purchased a?BITx40 and we thought it would be a good idea to check the SWR of his home made antenna before transmitting too much.
?
The problem we have run into is that his BITx40 only puts out a fraction of a Watt of power (.016 W) unless we are speaking into the microphone.? We are not able to use our?SWR bridge with?the?low power.
?
1. Is this normal for a BITX40?
?
2. Is there a standard way to increase the power to the antenna for these types of measurements?? (We could just set up a speaker next to the microphone to give consistent white noise input to the mic but this does not seem right.)?
?
?
Voltage measurements were taken with a multimeter on the output leads of?a 50 Ohm dummy load.
1.05V without speaking into the microphone (1.05V)^2 / 50 Ohm *.707 = .016?W (RMS power)
18V Loudly speaking into the microphone (18V)^2 / 50 Ohm *.707 = 4.58 W (RMS power)
?
Thanks,
Scott |
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Chris Cancilla
Have to look at that on Saturday, this will be a busy week. As for the standby, yes, it is receive actually. On Sun, May 17, 2020, 9:22 PM Evan Hand <elhandjr@...> wrote: Chris, --
__________________________ Chris Cancilla, W4CEC Raleigh, NC |
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Re: Test equipment recommendations
I suggest slowly figuring what you really need, watching for inexpensive club and merchant kits. A xtal oscillator makes a great signal generator or consider a pll signal generator from qrp labs or usr signals on the air. A qrp power meter is useful, but a diode detector and dvm can work also. Don't work too hard to find a used 100 mhz scope, one can be had cheaply if you are patient. Enjoy the journey.
Curt wb8yyy |
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Chris,
The only time that any of the 3 uBITX ( 6 PA transistors) that I have get warm is when running digital mode for an extended period of time.? I would check the bias setting of the finals.? The finals setup should be the same as the version 4 wireup instructions here:??and Tune-Up:? Note: ALL of my Raduino voltage regulators get HOT.? That is normal.? The regulator is on the board that is at right angles to the mainboard on the left side looking at the display. After writing the above, I realize that you should explain what you mean by standby.? There is only transmit and receive as far as I know. 73 Evan AC9TU |
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Re: Test equipment recommendations
¿ªÔÆÌåÓýNo.? I got it off of eBay.? I'd have to look it up (it's out in my shop).? It came from China as I remember.I've got a couple of those $10-$15 Radio Shack multimeters - one out back, and one in the tool box in my van.? They'll do 90% of what you usually need one for (especially with probes like for RF snooping).? In my shop/home lab, I needed one with additional functions - like peak hold and digital output - which gets occasional use.? For more really complicated stuff I turn to my good digitizer scope.? IMO, a good meter is something that as you get more experienced, the more you'll appreciate the 'extras' - especially if you don't have access to the really good equipment.? Mine isn't the best unit available, but it's accurate and precise enough for what I do - and it has adequate safety stuff built in.? I probably grab the meter about 80% of the time... my scopes come next (probably 10%), followed by the other equipment. On 5/17/20 8:10 PM, Reed N wrote: Hi Bob, |
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Chris Cancilla
I saw Dave Cassler on YouTube set up the mic and PPT on a pen cap.? It does work. One question y'all. The heatsinked transistors towards?the back get hot in standby? Do I need to find a fan of some kind for them? ___________________________
On Sun, May 17, 2020 at 8:27 PM Rick Price <rickprice48@...> wrote:
--
__________________________ Chris Cancilla, W4CEC Raleigh, NC |
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¿ªÔÆÌåÓýChris,
Good job! You would not believe how much trouble that little
4.7k resistor has caused over the last 3 years!? Glad it's all working
now.
?
Rick
KN4AIE
?
? From: [email protected] [mailto:[email protected]] On Behalf Of Chris Cancilla Sent: Sunday, May 17, 2020 8:22 PM To: [email protected] Subject: Re: [BITX20] uBITX v3 programming #arduino #ubitx Actually, all I did was add the 4.7 km resistor between the yellow and blue
wires on the Arduino cable ribbon and that put the voltage where it needed to
be. Then I made sure that the push to talk button that came with the kit was
jumpered between the yellow and red wires on the tuning knob. So now I have
access to all the bands and all the frequencies. On Sun, May 17, 2020, 7:47 PM Evan Hand <elhandjr@...> wrote:
I would clarify what Christopher is saying in that the PULLUP RESISTOR and 3.5 mm plug needs to be installed.? The key itself is optional. -- __________________________ Chris Cancilla, W4CEC Raleigh, NC |
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Chris Cancilla
Actually, all I did was add the 4.7 km resistor between the yellow and blue wires on the Arduino cable ribbon and that put the voltage where it needed to be. Then I made sure that the push to talk button that came with the kit was jumpered between the yellow and red wires on the tuning knob. So now I have access to all the bands and all the frequencies. On Sun, May 17, 2020, 7:47 PM Evan Hand <elhandjr@...> wrote: I would clarify what Christopher is saying in that the PULLUP RESISTOR and 3.5 mm plug needs to be installed.? The key itself is optional. --
__________________________ Chris Cancilla, W4CEC Raleigh, NC |
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Chris Cancilla
Thanks Evan, this is exactly what I needed. Mine did not have all this information in it. Now I can change bands and function so life is good. All I need to do is hook up the microphone and pull my antenna out of the shed and I should be able to run a test, but it may not be till next weekend because I have to work this week even though I am working from home. On Sun, May 17, 2020, 5:51 PM Evan Hand <elhandjr@...> wrote: I do not know of a v3 manual.? Here is a v4 which should be close: --
__________________________ Chris Cancilla, W4CEC Raleigh, NC |
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Re: Test equipment recommendations
Hi Bob,
For home/hobby use, I have a Best DT-9205M. It's not a high quality multimeter, but it measures AC and DC voltage and current, resistance, and capacitance. It's good enough for order of magnitude capacitance (is this a 0.1uF, or 1uF?), and reasonable on DC voltage readings. It's unfused on the current input, so I never use it for high current systems - that's just asking for trouble. For high current stuff, I borrow the high quality multimeters (with all the bells and whistles, like min/max hold, counters, and such) from work, but I can't remember the last time I needed to do that. I don't think buying a quality (expensive) multimeter would be a bad idea, and you're absolutely right about them lasting a LONG time (with proper care), but also don't think that it's necessary to buy something like a Fluke 289, BK Precision 393, or 121GW straight out of the gate. I whole-heartedly agree with you about reading and following your equipment's specs! That's what I was hoping to convey with the "know your tools' limitations" bit. Do you have a link to whatever kit you bought for the HF upconversion? Reed |
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Re: Test equipment recommendations
Laugh!!!?? I suggested a good meter because the ones I was thinking about had other useful functions like cap testing and better tolerance of spikes (plus the safety features you mentioned).? To that I'd add that multimeters as a general rule don't like HF (guess how I know)!? Some have a frequency counter function built in - but the models I've seen with that were limited in bandwidth - and as I'd learned, that maximum frequency and AC voltage IS the limit. Another suggestion to add - remember the specs and try to avoid exceeding them!
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I'd forgotten the general coverage receiver.? Thanks for bringing that up. As far as SDR, you can buy a bare-bones upconverter now that works pretty well, for not that much money.? I've got one - board and components only, but it's sensitive, rather good at rejecting signals above 30mhz, and doesn't seem to radiate much when used. (So far I've not seen any ghost signals from the upconverter - and I do watch for them.) Bob On 5/17/20 6:20 PM, Reed N wrote:
There's already a lot of good recommendations here, but thought I'd add my 2 cents. |
Vic WA4THR
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