You'd think so, but it's basically the same as any other monoband dipole.? Every dipole has a design frequency, but usually they're broadband enough to cover most of the band with an acceptable SWR.? If you're looking for an online calculator, this one will help you keep track of things like apex angle, height above ground, and wire/tubing/insulating effects (it's labeled Linked Antenna Designer, but you can set it to one frequency) .? If you're looking for antennas with a higher Q (and a narrower usable bandwidth) then you might check out the antennas group /g/antennas/topicsGood luck, John VA7JBE
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Re: Hans, please weigh in on suggested fixes or improvements
#qcx
Hello,
I have the same effect on my QCX. In SEMI mode, a weak signal is sent between the characters. Reducing R41 reduces it a bit, but it persists.
At the drain of BS170 there is a stable voltage? (on transmission frequency) around 0.7V ^ for the duration of the SEMI-BREAK break .Test with my IC7300: Signal is S9+10, SEMIBREAK break is S3 (Keyer on 1Wpm is helpful)
In my opinion, it is HF (from IC3A), which is coupled over from the gate to the drain, even if Q6 turns off the operating voltage.This HF would probably have to be shut down during SEMIBREAK break, as it probably happens with QSK or at the end of the SEMIBREAK break.
Reiner DL8LRZ
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On Sat, Sep 8, 2018 at 07:54 AM, Rick, DJ0IP wrote:
There's a lot to be said for using monoband dipoles, but they also have their downsides.
Say we hike to the top of a mountain with a dipole for our favorite band and find that band is mostly dead...
I think you misunderstand me.? I don't want to tune to one band, I really did mean one frequency, hopefully the sole 20m FT8 one shortly after Hans issues the U3S firmware upgrade.? I have no interest in CW or 'phone.? This is a pure beacon.? That should simplify construction, yes?
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There's a lot to be said for using monoband dipoles, but they also have their downsides.
Say we hike to the top of a mountain with a dipole for our favorite band and find that band is mostly dead.
It is nice to have alternatives.? Basically the coax fed dipole only works on its fundamental and 3rd harmonic.
Thus I prefer taking multi-band solutions with me such as the Aerial-51 Model 404-UL.
This gives me the possibility to work on most bands, 40m and above; in most cases without a matchbox.
- 73 Rick, DJ0IP
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Sorry about my poor math, guys.
50 / 3 = 17 Ohms, (not 33).
17 Ohms is definitely below the sweet spot of most antenna matchboxes.
?- Rick
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I built my QLG1 GPS module about 1? years ago. Lately, I¡¯ve been noticing when first powered up it seems to take a long time to acquire the satellites and produce the 1 PPS. I use it with a U3S and QCX.
I had an opportunity to work on another QLG1 and decided to check its battery voltage and saw that it was down in the millivolt region. I checked this list for other similar experiences and found it¡¯s a known issue, but other than delaying start up isn¡¯t much of a problem.
I peeled back the tab on my battery and found it to be the reported CR927 lithium primary cell and not a rechargeable. I decided I would seek out a rechargeable replacement.
I found one at Mouser priced at around $4.50, a Panasonic VL-1220/HFN with a diameter of a little over 12mm. It¡¯s only 2mm larger than the cell included with the kit and fits the available space nicely. The mounting tabs match the PC board.?
? ??
Installation was pretty straightforward except for unsoldering the negative side of the original coin cell from the ground plane which occupies both sides of the board. Some careful work with Solder-Wick and soldering flux helped the extraction a lot.
So far the battery is holding its charge and for now it seems like QLG1 doesn¡¯t take very long to get the 1 PPS signal¡.time will tell :-)
--Al
WD4AH
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Re: QCX display failure during transmit
#qcx
A 9V battery will not power the QCX.in Tx mode. ? Yes you can use a 12V motorcycle battery just fine.? For all power sources a 1A to 1.5 A fuse is a good idea although with any adequate power source a fault will most likely cause damage long before the fuse blows, just the nature of small feature size electronics. ? ?
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Crazy!
That chap does not have the fun of experimenting to see what can be done on a tiny plot.
But he does have the capability of deceiving us that our bits of wire work well:-)
73 Alan G4ZFQ
toggle quoted message
Show quoted text
Bob has a really good RX location and Beverages... This guy picked me up a few minutes ago:
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On Thu, Sep 6, 2018 at 02:10 PM, Alan G4ZFQ wrote:
Bob has a really good RX location and Beverages...
This guy picked me up a few minutes ago: Shouldn't present any problem!
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On Fri, Sep 7, 2018 at 07:33 AM, Rick, DJ0IP wrote:
If this interests you and you have a bit of time, you may download my MATCHBOX SHOOTOUT? at the bottom of this page:
Even more interesting was:
WHEN SHOULD YOU USE A MATCHBOX ?
ANSWER: ?Hopefully Never! ?. . . because ALL matchboxes add unwanted losses!
...and your following points which were sort of my objects in a very simplified, single-frequency dipole antenna design that will work and (hopefully) do this one thing with high efficiency.
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Re: QCX display failure during transmit
#qcx
. Using standard 9v battery as power supply.
Is this an insufficient power problem? Can I use a motorcycle battery to power the QCX? Don¡¯t want to blow it up. The only "standard" 9V battery I know is totally inadequate to supply the transmit current of a QCX. Yes a motorcycle battery will. Use a maximum 1 Amp fuse, it is also capable of doing much damage if a fault should occur. 73 Alan G4ZFQ
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QCX display failure during transmit
#qcx
QCX boots up, aligns, receives. With keyer set in straight, practice mode ON. Can use external keyer or built in keyer. Generates tone, decoder reads signals. Set practice mode to OFF. Attach dummy load, and display blanks out when internal or external keyer is pressed. Using standard 9v battery as power supply.?
Is this an insufficient power problem? Can I use a motorcycle battery to power the QCX? Don¡¯t want to blow it up.
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Rick/DJ0IP
?
Thank you very much for:
?
- Taking the time to perform extensive research
- Share this highly valuable information with the rest of us
?
Mark Lunday, WD4ELG
Greensboro, NC? FM06be
wd4elg@...
SKCC #16439? FISTS #17972? QRP ARCI #16497
?
?
?
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Juan HK6J
QRP is usually seen as 10 watts or less.
QRPp is usually seen as 1 watt or less.
Arv? K7HKL
_._
Hello, what does mean (QRPp)?
Tnx Juan HK6J
Juan Herrera
Enviado desde mi iPhone
El 7/09/2018, a la(s) 8:34 a. m., Braden Glett < bradenglett@...> escribi¨®:
I'm certainly no expert, but I'll tell you my experience. I run QRPp whenever it's possible given summer QRN and poor propagation. I don't like the "listen and pounce" approach one bit, so I always call CQ. I will run as low as 100 mW which is as low as
my radio can be dialed down to. If I can't get a reply within one or two CQ calls at 100 mW, I start dialing the power up until I do get a response. Depending on conditions, that can go as high as 5W which of course isn't QRPp but then reality is that QRPp
isn't always practical in all conditions.
I use a 600 foot delta loop, that is up 35 feet at the feedpoint, and up 50 feet elsewhere. It is fed with balanced feedline (400 ohm from MFJ) which of course virtually eliminates all feedline losses. I'm sure a much smaller loop would work pretty well, too,
but obviously not as well as 600 feet does. This antenna is always used with an automatic antenna tuner.
Summer QRN makes QRPp more difficult on the one or two bands that are reliably open at this point in the sunspot cycle, 40 and 30. Last winter, 100 mW worked very well most of the time, even for rag chewing. Now granted, I wasn't making contacts with NZ, but
instead contacts in the eastern US and Canada, from SW Ohio. I think my furthest contact was Puerto Rico for QRPp. If I can't get at least a 57 report, I dial up the power a little, as I'm not trying to torture the person on the other end.
Of course, I am working CW since it is really the only thing that works well with QRPp, at least in these conditions.
Just my 2 cents worth, for what it's worth.?
Ciao and 73,
Brady KD8ZM
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Tnx Andy, my QCX/20 comes out with 2,8 watts
HK6J?
Juan Herrera
Enviado desde mi iPhone
El 7/09/2018, a la(s) 9:33 a. m., Rick, DJ0IP < Rick@...> escribi¨®:
toggle quoted message
Show quoted text
Mark's reply was very good.? I'd like to add a bit if I may.
Asking if a matchbox (not tuner) has a lot of loss can only be answered with "it depends".
All matchboxes have sweetspots (frequency and impedance ranges) where the loss is so low that it is negligible.
I have a drawing showing this, here: ??
The ARRL defines this to be less than 10% loss.
So the answer to whether or not the matchbox has noticeable loss is, it depends on whether it is operating within its sweetspot or not.
In addition, the ARRL has tested a couple dozen matchboxes over the past 20 years.
I have summarized their findings into a single, MONSTER Excel spreadsheet.
It clearly shows the sweetspots of each matchbox model tested.
Unfortunately, you need to know the impedance of your antenna system
where it connects to the matchbox, not just the SWR.
A 3:1 SWR can be either 150 Ohms or 33 Ohms.
150 Ohms is within the sweetspot of most matchboxes.
33 Ohms is often not within the sweetspot. ?
So just knowing the SWR (alone) does not always give us the right answer.
If this interests you and you have a bit of time, you may download my MATCHBOX SHOOTOUT? at the bottom of this page:
Remember guys, a dB is a dB, whether we're running 500 Watts or 50 mW.
If my signal happens to be 55(9) with 100mW, one dB of loss is meaningless - unless the guy's noise level is also 55 (hi).
73 - Rick, DJ0IP
May the Sunspots be with us!
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Mark's reply was very good.? I'd like to add a bit if I may.
Asking if a matchbox (not tuner) has a lot of loss can only be answered with "it depends".
All matchboxes have sweetspots (frequency and impedance ranges) where the loss is so low that it is negligible.
I have a drawing showing this, here: ?http://www.dj0ip.de/antenna-matchboxes/perfect-matchbox/?
The ARRL defines this to be less than 10% loss.
So the answer to whether or not the matchbox has noticeable loss is, it depends on whether it is operating within its sweetspot or not.
In addition, the ARRL has tested a couple dozen matchboxes over the past 20 years.
I have summarized their findings into a single, MONSTER Excel spreadsheet.
It clearly shows the sweetspots of each matchbox model tested.
Unfortunately, you need to know the impedance of your antenna system where it connects to the matchbox, not just the SWR.
A 3:1 SWR can be either 150 Ohms or 33 Ohms.
150 Ohms is within the sweetspot of most matchboxes.
33 Ohms is often not within the sweetspot. ?
So just knowing the SWR (alone) does not always give us the right answer.
If this interests you and you have a bit of time, you may download my MATCHBOX SHOOTOUT? at the bottom of this page:
Remember guys, a dB is a dB, whether we're running 500 Watts or 50 mW.
If my signal happens to be 55(9) with 100mW, one dB of loss is meaningless - unless the guy's noise level is also 55 (hi).
73 - Rick, DJ0IP
May the Sunspots be with us!
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Hi Juan,
QRPp is transmitting with less than 1 watt.
Andy
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Re: Repair of a non operational QCX 40
I have repaired a few. Be happy to take a look. -- > I finally got it all together...now I can't remember where I put it< Wes
AE6ZM
Sierra Vista, AZ
?
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Hello, what does mean (QRPp)?
Tnx Juan HK6J
Juan Herrera
Enviado desde mi iPhone
El 7/09/2018, a la(s) 8:34 a. m., Braden Glett < bradenglett@...> escribi¨®:
toggle quoted message
Show quoted text
I'm certainly no expert, but I'll tell you my experience. I run QRPp whenever it's possible given summer QRN and poor propagation. I don't like the "listen and pounce" approach one bit, so I always call CQ. I will run as low as 100 mW which is as low as
my radio can be dialed down to. If I can't get a reply within one or two CQ calls at 100 mW, I start dialing the power up until I do get a response. Depending on conditions, that can go as high as 5W which of course isn't QRPp but then reality is that QRPp
isn't always practical in all conditions.
I use a 600 foot delta loop, that is up 35 feet at the feedpoint, and up 50 feet elsewhere. It is fed with balanced feedline (400 ohm from MFJ) which of course virtually eliminates all feedline losses. I'm sure a much smaller loop would work pretty well, too,
but obviously not as well as 600 feet does. This antenna is always used with an automatic antenna tuner.
Summer QRN makes QRPp more difficult on the one or two bands that are reliably open at this point in the sunspot cycle, 40 and 30. Last winter, 100 mW worked very well most of the time, even for rag chewing. Now granted, I wasn't making contacts with NZ, but
instead contacts in the eastern US and Canada, from SW Ohio. I think my furthest contact was Puerto Rico for QRPp. If I can't get at least a 57 report, I dial up the power a little, as I'm not trying to torture the person on the other end.
Of course, I am working CW since it is really the only thing that works well with QRPp, at least in these conditions.
Just my 2 cents worth, for what it's worth.?
Ciao and 73,
Brady KD8ZM
|
I'm certainly no expert, but I'll tell you my experience. I run QRPp whenever it's possible given summer QRN and poor propagation. I don't like the "listen and pounce" approach one bit, so I always call CQ. I will run as low as 100 mW which is as low as my radio can be dialed down to. If I can't get a reply within one or two CQ calls at 100 mW, I start dialing the power up until I do get a response. Depending on conditions, that can go as high as 5W which of course isn't QRPp but then reality is that QRPp isn't always practical in all conditions.
I use a 600 foot delta loop, that is up 35 feet at the feedpoint, and up 50 feet elsewhere. It is fed with balanced feedline (400 ohm from MFJ) which of course virtually eliminates all feedline losses. I'm sure a much smaller loop would work pretty well, too, but obviously not as well as 600 feet does. This antenna is always used with an automatic antenna tuner.
Summer QRN makes QRPp more difficult on the one or two bands that are reliably open at this point in the sunspot cycle, 40 and 30. Last winter, 100 mW worked very well most of the time, even for rag chewing. Now granted, I wasn't making contacts with NZ, but instead contacts in the eastern US and Canada, from SW Ohio. I think my furthest contact was Puerto Rico for QRPp. If I can't get at least a 57 report, I dial up the power a little, as I'm not trying to torture the person on the other end.
Of course, I am working CW since it is really the only thing that works well with QRPp, at least in these conditions.
Just my 2 cents worth, for what it's worth.?
Ciao and 73,
Brady KD8ZM
|
TrueBlue
Rick, DJ0IP
N3MNT
M0RON
Wes WB7BR
Braden Glett