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Hi. I tested mine using another radio. Short length of just coax from the recivibg one. Then proper antenna on the other. Transmit abs as the receiving test, radio has little antenna it only gets a week signal but still enough to prove it is transmiting.?
If that test OK, get a friend to give you a shout and work from there.?
Vaughn
I¡¯ve been testing my new v6 it seems to receive well I¡¯ve heard several stations. Unfortunately I don¡¯t have an HF SWR meter to test with. I now suspect I¡¯m not transmitting. I tried listening (using a WebSDR site) to my own transmission ?but I hear nothing. Anyone have any suggestions?
73
Mick VA3EPM
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On Wed, Jan 8, 2020 at 06:41 PM, Mick wrote:
Unfortunately I don¡¯t have an HF SWR meter to test with.
Free shipping:
* No snark intended; it's just a good buy and is a good part of any ham station's inventory. -Ted ?K3RTA ?
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Thanks Ted,
I wondering if my mic element isn¡¯t working should I hear a carrier on 40 meter LSB? The mic led lights and the relays switch when I key it, but no audio that I can discern.
:-)
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?There is always the possibility of a bad mic element though I'd think it rare. Double check polarity, etc.? Yes, a nearby receiver may hear a touch of carrier in the background especially if there are a few inches of wire poking out of its antenna connector [which I recommend]. As long as we're speaking of carriers, have you wired in the CW pull-up resistor to the CW wires?? If so, try grounding the end that would have gone to a key. That will hopefully put out tons of carrier!? If that works, then we only have to worry about the mic wiring.?
If you did get carrier for CW, then try de-soldering the mic and separate the mic "hi" away from the earth/ground. Key the radio while listening to your backup receiver on freq and touch the mic "hi" line with a moist finger. You should hear some light buzzing from stray electric mains energy.? If not, that's troublesome. If you do, then check that there is voltage (+/- 12vdc) on this mic "hi" line, which it needs to have. No volts on this? Also troubling.? If Yes, then the element might be bad after all.
How about if we do these things and report back, please?
Ted
K3RTA
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I¡¯m having similar symptoms on mine: CW transmits fine, I can read power on my meter and a WebSDR heard my beeping. But SSB appears not to be transmitting anything. ?My local ¡°other radio¡± hears audio, but they¡¯re feet away from each other. The power meter reads 0.00W on SSB when I¡¯m talking into it, and I couldn¡¯t hear a thing on several WebSDRs I tried.?
I haven¡¯t had a chance to really dive into it. Next step is to put it into a dummy load and look at it on a scope to measure the voltage (and therefore power) it¡¯s putting out. My suspicion was audio, until I heard audio on my other radio in the shack. But the finals are fine because CW gets out. So, I¡¯m really at a loss until I start poking around and measuring.?
Which I¡¯ll do when I get back home from vacation.?
-Mark
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On Jan 9, 2020, at 10:47 AM, Ted via Groups.Io <k3rta@...> wrote:
??There is always the possibility of a bad mic element though I'd think it rare. Double check polarity, etc.? Yes, a nearby receiver may hear a touch of carrier in the background especially if there are a few inches of wire poking out of its antenna connector [which I recommend]. As long as we're speaking of carriers, have you wired in the CW pull-up resistor to the CW wires?? If so, try grounding the end that would have gone to a key. That will hopefully put out tons of carrier!? If that works, then we only have to worry about the mic wiring.?
If you did get carrier for CW, then try de-soldering the mic and separate the mic "hi" away from the earth/ground. Key the radio while listening to your backup receiver on freq and touch the mic "hi" line with a moist finger. You should hear some light buzzing from stray electric mains energy.? If not, that's troublesome. If you do, then check that there is voltage (+/- 12vdc) on this mic "hi" line, which it needs to have. No volts on this? Also troubling.? If Yes, then the element might be bad after all.
How about if we do these things and report back, please?
Ted
K3RTA
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Hold the presses!!!
It seems I forgot that the CW pull-up and paddle resistors are part of the V6 board, now, so there's no need (and possibly a problem) in adding anything other than a key, to the CW lines.? Simply grounding out the correct wire ought to demonstrate RF energy somewhere and a nearby receiver will hear it.
73,
Ted K3RTA
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Ted,
I tried keying CW as you suggest it all appears and sounds like it¡¯s working I just don¡¯t have a nearby receiver I know is working that I can verify with. Tonight I¡¯m meeting with some local hams and I¡¯ll try to set up a net with them. I¡¯ll let you know the outcome. Thanks for the help.
73
Mick VA3EPM?
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Note that CW-KEY unbalances the first mixer at D1,D2, allowing CLK2 out to the power amp.
CLK2 from the Si5351 is at the transmit frequency during CW transmit.
CLK0 and CLK0 are disabled during CW transmit.
Having a healthy signal in CW mode proves out the first mixer and the power amp from Q90 through Q95.
It does not demonstrate that the modulator, 11.059mhz crystal filter, 11.059mhz IF amp,
second mixer at D3,D4, 45mhz filter,?or the 45mhz IF amp are working properly.?
If the rig powers up without immediately going into CW transmit mode,
then there is probably a pullup resistor on KEYER line into the Nano.
On the V6, these pullups are included on the main board, labeled R2 and R3 in the lower left of the schematic drawing.
On V3,V4 and V5 uBitx boards, they had to be added by the user at the keyer jack.
The two different pullups give a different voltage to the Nano A6 pin for the dit paddle vs the dah paddle.
The ADC in the Nano constantly reads the voltage to see if a paddle has been pressed.
Since A6 (and A7) are analog inputs only (no digital IO cell), they do not have
a firmware configurable pullup resistor inside the ATMega328P processor like the A0,1,2,3,4,5 pins do.
?
Jerry, KE7ER?
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On Thu, Jan 9, 2020 at 07:46 AM, Ted wrote:
There is always the possibility of a bad mic element though I'd think it rare. Double check polarity, etc.? Yes, a nearby receiver may hear a touch of carrier in the background especially if there are a few inches of wire poking out of its antenna connector [which I recommend]. As long as we're speaking of carriers, have you wired in the CW pull-up resistor to the CW wires?? If so, try grounding the end that would have gone to a key. That will hopefully put out tons of carrier!? If that works, then we only have to worry about the mic wiring.?
If you did get carrier for CW, then try de-soldering the mic and separate the mic "hi" away from the earth/ground. Key the radio while listening to your backup receiver on freq and touch the mic "hi" line with a moist finger. You should hear some light buzzing from stray electric mains energy.? If not, that's troublesome. If you do, then check that there is voltage (+/- 12vdc) on this mic "hi" line, which it needs to have. No volts on this? Also troubling.? If Yes, then the element might be bad after all.
How about if we do these things and report back, please?
Ted
K3RTA
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Correction:
It is R2 on the Raduino-TFT schematic (new for the v6 uBitx) that is the pullup to 5v for KEYER.
R2 and R3 on the main uBitx board are used to pull down that KEYER signal to initiate a dit or dah CW transmission.
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On Thu, Jan 9, 2020 at 08:39 AM, Jerry Gaffke wrote:
On the V6, these pullups are included on the main board, labeled R2 and R3 in the lower left of the schematic drawing.
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A good SWR meter can be got from Ebay for not very much. I have never owned an antenna analyzer - a SWR meter works just fine for a lot less.
Hi. I tested mine using another radio. Short length of just coax from the recivibg one. Then proper antenna on the other. Transmit abs as the receiving test, radio has little antenna it only gets a week signal but still enough to prove it is transmiting.?
If that test OK, get a friend to give you a shout and work from there.?
Vaughn
I¡¯ve been testing my new v6 it seems to receive well I¡¯ve heard several stations. Unfortunately I don¡¯t have an HF SWR meter to test with. I now suspect I¡¯m not transmitting. I tried listening (using a WebSDR site) to my own transmission ?but I hear nothing. Anyone have any suggestions?
73
Mick VA3EPM
--
Alex Netherton, W5ALX
Buncombe County NC, EM85ro
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just to throw my own experience in here, I was suspecting the mic was bad too, but I also didn't have a proper low power meter. This morning I found an old power meter with a 10W range and tested again. No power out on SSB. I also find the mic I used with my version 3, and I see about 4 Watts out with a hearty Hallooooo! Into the mic.?
I'll take it apart this weekend and see what's up, but I also have 2 of the Pacific Antenna qrpkits mics to assemble and I hear good things about those.? I'll report back.? Sent from my Burroughs B7700 - Neil Goldstein, W2NDG
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One trick I've used? is to see how hot a 50 ohm resistor gets, Compare that to how hot a resistor on a variable voltage DC supply gets, vary the voltage till the heating is about the same then compute watts from V*V/R A diode RF probe is trivial to build, though involves a wee bit more math to interpret properly.. V*V/R = Watts, so V*V=Watts*R, and five watts into 50 ohms is sqrt(Watts*50ohms) = sqrt(5*50) = 15.8 volts rms. If the RF probe is peak reading, you will see 15.8 * 1.414 = 22.4 volts peak into a DC voltmeter. Many RF probe designs include a 4.7meg scaling resistor so it reads rms? on the assumption that the RF is a sine wave and the DVM has an input resistance of around 10meg. Those are some very large assumptions, I prefer to have it honestly tell me the peak voltage. Let's assume a 1n4148 diode has a forward drop of about 0.6 volts, a schottky Bat54s a drop of 0.2 volts. So errors get beyond 10% if below 6v peak for the 1n4148, or (6/1.414)*(6/1.414)/50 = 0.35 Watts. And errors get beyond 10% if below 2v peak for a Bat54s, or (2/1.414)*(2/1.414)/50 = 0.04 Watts. Taking that diode drop into account, the Bat54s can give useful results to well under a milliwatt. If you want an SWR meter that also shows power, consider Diz's $12 Tandem Match kit: ? ?? Item 18:?? If you want a full antenna analyzer, consider the nanoVNA and it's newer variants, as cheap as $40: ? ?? /g/nanovna-users/messages?expanded=1A steep learning curve, but very powerful. Jerry, KE7ER
On Thu, Jan 9, 2020 at 01:50 PM, Alex Netherton wrote:
A good SWR meter can be got from Ebay for not very much. I have never owned an antenna analyzer - a SWR meter works just fine for a lot less.
Hide quoted text
?
Hi. I tested mine using another radio. Short length of just coax from the recivibg one. Then proper antenna on the other. Transmit abs as the receiving test, radio has little antenna it only gets a week signal but still enough to prove it is transmiting.?
?
If that test OK, get a friend to give you a shout and work from there.?
?
Vaughn
I¡¯ve been testing my new v6 it seems to receive well I¡¯ve heard several stations. Unfortunately I don¡¯t have an HF SWR meter to test with. I now suspect I¡¯m not transmitting. I tried listening (using a WebSDR site) to my own transmission ?but I hear nothing. Anyone have any suggestions?
73
Mick VA3EPM
?
?
--
Alex Netherton, W5ALX
Buncombe County NC, EM85ro
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We need a more objective criterion ti assess what is happening. If the local radio ia picking up the modulation then the mic can't be a suspect. If the receiver is working then there is a negligible chance that the ssb tx ia busted. Rememeber that it was shipped working. Can you measure the power supply current? If you can, then measure how much it draws when you shout 'Haaaaaallow' into the mic. The current draw increase on 7mhz should be over 1.5A at peak. I hope you have used a matched antenna.
- f
On Fri 10 Jan, 2020, 7:06 AM Jerry Gaffke via Groups.Io, <jgaffke= [email protected]> wrote: One trick I've used? is to see how hot a 50 ohm resistor gets,
Compare that to how hot a resistor on a variable voltage DC supply gets,
vary the voltage till the heating is about the same then compute watts from V*V/R
A diode RF probe is trivial to build, though involves a wee bit more math to interpret properly..
V*V/R = Watts, so V*V=Watts*R, and five watts into 50 ohms is sqrt(Watts*50ohms) = sqrt(5*50) = 15.8 volts rms.
If the RF probe is peak reading, you will see 15.8 * 1.414 = 22.4 volts peak into a DC voltmeter.
Many RF probe designs include a 4.7meg scaling resistor so it reads rms?
on the assumption that the RF is a sine wave and the DVM has an input resistance of around 10meg.
Those are some very large assumptions, I prefer to have it honestly tell me the peak voltage.
Let's assume a 1n4148 diode has a forward drop of about 0.6 volts, a schottky Bat54s a drop of 0.2 volts.
So errors get beyond 10% if below 6v peak for the 1n4148, or (6/1.414)*(6/1.414)/50 = 0.35 Watts.
And errors get beyond 10% if below 2v peak for a Bat54s, or (2/1.414)*(2/1.414)/50 = 0.04 Watts.
Taking that diode drop into account, the Bat54s can give useful results to well under a milliwatt.
If you want an SWR meter that also shows power, consider Diz's $12 Tandem Match kit:
? ??
Item 18:??
If you want a full antenna analyzer, consider the nanoVNA and it's newer variants, as cheap as $40:
? ??/g/nanovna-users/messages?expanded=1
A steep learning curve, but very powerful.
Jerry, KE7ER
On Thu, Jan 9, 2020 at 01:50 PM, Alex Netherton wrote:
A good SWR meter can be got from Ebay for not very much. I have never owned an antenna analyzer - a SWR meter works just fine for a lot less.
Hide quoted text
?
Hi. I tested mine using another radio. Short length of just coax from the recivibg one. Then proper antenna on the other. Transmit abs as the receiving test, radio has little antenna it only gets a week signal but still enough to prove it is transmiting.?
?
If that test OK, get a friend to give you a shout and work from there.?
?
Vaughn
I¡¯ve been testing my new v6 it seems to receive well I¡¯ve heard several stations. Unfortunately I don¡¯t have an HF SWR meter to test with. I now suspect I¡¯m not transmitting. I tried listening (using a WebSDR site) to my own transmission ?but I hear nothing. Anyone have any suggestions?
73
Mick VA3EPM
?
?
--
Alex Netherton, W5ALX
Buncombe County NC, EM85ro
|
The Antuino from hfsignals is also well worth considering.
It can measure the SWR of an antenna, and with an appropriate resistive attenuator
it can measure the power output of a transmitter.
Unlike any of the other instruments mentioned, it can measure very low level RF signals
and can scan the entire HF radio spectrum looking for spurs and harmonics.
So can be a spectrum analyzer of sorts (which the nanoVNA cannot do).
The antuino should be easier to learn to use than a nanoVNA.
The thing that makes the nanoVNA more powerful (and more difficult) is that it can measure
resistance and reactance separately, rather than lumping them together as SWR does.
Either the nanoVNA or the Antuino could be used for determining the passband of a filter,
but the nanoVNA would also give you information about the phase difference
between the voltage and current..
Jerry
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Show quoted text
On Thu, Jan 9, 2020 at 05:35 PM, Jerry Gaffke wrote:
One trick I've used? is to see how hot a 50 ohm resistor gets,
Compare that to how hot a resistor on a variable voltage DC supply gets,
vary the voltage till the heating is about the same then compute watts from V*V/R
A diode RF probe is trivial to build, though involves a wee bit more math to interpret properly..
V*V/R = Watts, so V*V=Watts*R, and five watts into 50 ohms is sqrt(Watts*50ohms) = sqrt(5*50) = 15.8 volts rms.
If the RF probe is peak reading, you will see 15.8 * 1.414 = 22.4 volts peak into a DC voltmeter.
Many RF probe designs include a 4.7meg scaling resistor so it reads rms?
on the assumption that the RF is a sine wave and the DVM has an input resistance of around 10meg.
Those are some very large assumptions, I prefer to have it honestly tell me the peak voltage.
Let's assume a 1n4148 diode has a forward drop of about 0.6 volts, a schottky Bat54s a drop of 0.2 volts.
So errors get beyond 10% if below 6v peak for the 1n4148, or (6/1.414)*(6/1.414)/50 = 0.35 Watts.
And errors get beyond 10% if below 2v peak for a Bat54s, or (2/1.414)*(2/1.414)/50 = 0.04 Watts.
Taking that diode drop into account, the Bat54s can give useful results to well under a milliwatt.
If you want an SWR meter that also shows power, consider Diz's $12 Tandem Match kit:
? ??
Item 18:??
If you want a full antenna analyzer, consider the nanoVNA and it's newer variants, as cheap as $40:
? ??/g/nanovna-users/messages?expanded=1
A steep learning curve, but very powerful.
Jerry, KE7ER
|
Ashhar,
I draw .322 on RX and 1.47 Cw and shouting the loudest I can I draw about 1.5 amps at exactly 12 Vdc. I¡¯m running a new MFJ 1984 endfed antenna that is supposed to be tuned at the factory, however until I get an SWR meter I won¡¯t know for sure.
73
Mick VA3EPM?
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Mick,
An end-fed antenna at it's design frequency (where it is a 1/2 wave say at 7 MHz and thus about 66 feet long) will have a very high impedance at the feed point (one end).? You typically can't just hook it to your antenna jack, and expect to get any power into it.? The MFJ-1984 has a so-called matching transformer (more about that later).
Various end fed feed arrangements are typically used, including 9:1 (or higher) transformers at the feed point.? That may help get the typically 1-2 thousand ohm impedance down to 100-200 ohms or so, which can get it in range of most "antenna tuners".? Also adding a counter-poise ("ground" line) there, to help stop RF from coming back down the outside of the coax shield, which can raise havoc with your rig.? Such a setup almost certainly will require a matching network ("antenna tuner") to match whatever impedance you are seeing from the antenna/transformer arrangement to your coax/transmitter.
End-feds are popular with the QRP crowd, especially for portable operations, because you only need to have a single support (nearby tree) to throw the far end up into.? But care must be exercised in feeding such an antenna, because on the design frequency (and even harmonics) it will be far from the typical 50 ohm output of modern solid-state transmitters.
Now, the MFJ-1984 is making some pretty wild claims for how well their end-fed antenna matches on practically all bands 40-10M WITHOUT A TUNER (WTF?)
I call snake oil.? If it really does show a low SWR across all those bands, it likely has a 50 ohm or similar resistor in the housing across the feedline.? This will of course, give you a nice low SWR everyplace, but it will also dissipate most of your signal in that resistor, rather than radiating over the air.? There was an infamous shortened dipole that had a center insulator that was potted and shielded, making it difficult to see what was inside, even with X-rays.? Eventually, they were found out that the system had a big 50 ohm resistor in the center insulator housing, and thus, any band looked good, but it radiated very poorly.
You may be able to hear well, in particular on 40M, because the signals on that band are pretty loud, and you can hear OK there with a severely compromised antenna.? But, it will be very frustrating, because most stations will not be able to hear you.? Compound that with running under 10W, and you will be very frustrated, indeed.
Please start with a simple resonant (cut to frequency for that band) dipole antenna, center fed with 50 ohm coax.? You can use a 1:1 CURRENT balun at the feed point, if you want to stop antenna currents from coming back down the shield of the coax, but at the moment, that might considered an unnecessary complication.? Get it up in the air at least 30 feet or so, and try that on your setup.
A simple resonant dipole is VERY?efficient, and say if you do this for 40M, you will be pleased with getting out and making contacts (especially on CW for QRP) out to several hundred miles.? At only 30 feet, it won't be a DX champ, because the angle of radiation will be somewhat high, but it will fine for closer in work.
Hope that helps,
73,
-- Dave, N8SBE
-------- Original Message --------
Subject: Re: [BITX20] New uBITX Ver. 6 Assembled Today
From: "Mick" < Mgsebele@...>
Date: Fri, January 10, 2020 6:16 am
To: [email protected]
Ashhar, I draw .322 on RX and 1.47 Cw and shouting the loudest I can I draw about 1.5 amps at exactly 12 Vdc. I¡¯m running a new MFJ 1984 endfed antenna that is supposed to be tuned at the factory, however until I get an SWR meter I won¡¯t know for sure. 73 Mick VA3EPM?
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Dave,
Thanks for the feedback and tutorial. I selected that antenna specifically because of the the no tuner claim. Unfortunately I think your snake oil call is on the money! That¡¯s the bad news. The good news is I can build a 40 meter dipole reasonably easily and get on the air at least on one band. That will be another days project.
73
Mick VA3EPM?
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Well, there is this........? an end-fed multibrand using a trap.
http://www.infotechcomms.net/downloads/Multi_band_EFHW.pdf
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Ted,
Thanks for that.? Lots of experimental fiddly tuning with that, but with some effort, maybe will pay off.
I notice that it didn't appear that he was able to get any useful WSPR results on 20M and above, due to band closures, so we don't really know how well any of the configurations tried worked on the higher bands.
I'd still be in favor of a simple resonant dipole to start with, and if nothing else, it will give you something to compare against if you want to experiment with other designs.
73,
-- Dave, N8SBE
-------- Original Message --------
Subject: Re: [BITX20] New uBITX Ver. 6 Assembled Today
From: "Ted via " <k3rta@...>
Date: Fri, January 10, 2020 6:05 pm
To: " [email protected]" < [email protected]>
Well, there is this........? an end-fed multibrand using a trap.
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After doing some tests and working with a local Elmer (thanks Bill) we have confirmed the v6 is transmitting we noticed the audio was weak and muffled so I¡¯m going to upgrade the mic and work on improving the antenna. Thanks for all the help and advice.
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Show quoted text
On Jan 10, 2020, at 6:05 PM, Ted via Groups.Io <k3rta@...> wrote:
? Well, there is this........? an end-fed multibrand using a trap.
http://www.infotechcomms.net/downloads/Multi_band_EFHW.pdf
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Vaughn
Ted
Mick
Smitty, N6MTS
Alex Netherton
Neil Goldstein