Re: BITX QSO Afternoon/Night, Sunday, February 25, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Tried 7.277 a few times qrp and at about 30W nothing heard going to call on 80m with my ubitx 3.977 -- David
?N8DAH
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I did some post-mortem examination on the audio output stage today after U1 and R75 went up in smoke.? Here is what I found:
As Jerry pointed out above, plugging in a mono jack to the ¡®phones¡¯ jack will short the output to ground.? I believe that this is exactly what I did.? I tried to plug in an extension speaker with a mono jack I¡¯m pretty sure that that is when the failure happened.
?I was able to carefully remove U1 and there appears to be no damage to the board or any traces.? I also removed what was left of R75 and cleaned up the board with alcohol.? Interestingly, a pad on one side of R75 appeared to have little or no solder. This was the side of R75 attached to pin 6 of U1 (input 2 +).
?
?I carefully applied power to the unit ¨C all seems well except no audio output of course.? Transmit on SSB and CW are working.? I could hear a modulated SSB signal on another receiver which sounded OK.? I probed the connection to U1 pin 7 (input 1 +) with an oscilloscope and was able to see a signal.? I then tuned the rig to 14.074 (20 meter FT8) and sure enough, every 15 seconds the signal would briefly disappear and then reappear for another 15 seconds.? This indicates to me that the previous audio stage is working ¨C here¡¯s hoping anyway.? I thought about injecting this into an external audio amp but decided not to push my luck ¨C I¡¯m just going to wait for the parts to arrive and work on a case in the meantime.
?
Did not mean to ramble so much, but decided to post this in case it might help someone else. Incidentally, I probably qualify as an old timer ¨C first licensed in 1960.? Still learning something every day and making rookie mistakes!
?
Bill
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
According to my cheap wattmeter (that I know reads low) I'm putting about 120 watts into a 135' wire (and 9:1 balun) at 15'. That same electric fence wire I mentioned. Yes, 15 feet above ground - I recently measured it for those wondering about my previous comments on it. With a cheap MFJ tuner I've worked 160 and 75 regularly. Without a tuner used it on 40 with my B40 and worked a bunch of digital and I have a flat SWR on all of 20 meters.
Currently I'm using a cobra antenna (not the CB radio cobra, it's named after it's style, google it, easy to make) at 40' sloping down to about 10-15'. With a tuner I get a near flat SWR on all bands 160-10.
Vince.
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On 02/25/2018 06:59 PM, Mark via Groups.Io wrote: Hi Vince,
For QRP I'd only need #17?
There's a write-up on this type of wire purchased from tractor supply
stores, entitled, Does wire gauge (size) make any difference for
vertical antenna radials?, at eHam.net.
They say that some antenna manufactures suggest 14. I guess that is
possibly because it is used for base stations with 100 or more watts.
However, for my specific QRP & mobile situation, maybe 17 would be fine.
It would also be a bit lighter.
Would reception improve if it were copper? Or, maybe for something like
this it wouldn't really matter.
Thanks,
Mark
--
Michigan VHF Corp.
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Re: BITX QSO Afternoon/Night, Sunday, February 25, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Same here!
--
John - WA2FZW
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Re: BITX QSO Afternoon/Night, Sunday, February 25, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere
I'm here right now, S1 noise level, not hearing anyone.
Vince - KA8CSH.
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On 02/25/2018 06:48 PM, at91r40008 wrote: Don't here anybody. I called but no taker.
--
73, Yvon NU6I
--
Michigan VHF Corp.
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
Hi Vince,
For QRP I'd only need #17?
There's a write-up on this type of wire purchased from tractor supply stores, entitled, Does wire gauge (size) make any difference for vertical antenna radials?, at eHam.net.
They say that some antenna manufactures suggest 14. I guess that is possibly because it is used for base stations with 100 or more watts.
However, for my specific QRP & mobile situation, maybe 17 would be fine. It would also be a bit lighter.
Would reception improve if it were copper? Or, maybe for something like this it wouldn't really matter.
Thanks,
Mark
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Hi Dale, I disconnected D20 from the input of the attenuation pad going into the tx amp and the carrier was reduced but still there. I was wondering if the 12 MHz oscillator output could be leaking into the tx amp. I also get a large burst of of RF when the ptt is pressed. I read in earlier posts that they never found a solution to the ptt RF burst problem. I also read that with the diodes and the pot that it was normal to get a 1vpp output at the antenna with no audio input. Would you mind you mind discussing this problem on the land line.? Thank You Bob WB2TFG ex
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Re: BITX QSO Afternoon/Night, Sunday, February 25, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Don't here anybody. I called but no taker.
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73, Yvon NU6I
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
Thank you Mike,
I am going to be copying these instructions (along with lots of other comments) into my amateur radio notes text file.
I didn't realize I'd get this much of a response! It's like having a custom-designed lesson.
I don't take it for granted.
There are YouTube instructions on this that I'll combine with your instructions. Making an antenna doesn't seem that difficult. A few basic tools. The most expensive one (that would be worth the investment) may be an SWR or antenna tuner.
Appreciate it,
Mark
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Re: Raduino Replacemnt, COMING SOON!
Ok, Well, thanks for spotting this error. Lucky I only have 20 of these boards on the first order... Easy enough fix as per Jerry's post. I suggect just replacing the last 3 headers with the 104 caps with their legs bent in opposite directions, as cutting the tracks will be difficult, they are only 0.5mm... I have fixed up the Rev.01 board for the next run, I have had to remove one of the mounting holes for the Si5351, but thats OK, I was only going to mount it with the header pins anyway... 1206 SMD should work fine on those TH pads if you choose to do that also... TOP:  BOTTOM:  73, VK4PLN
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
Jerry,
I think I understand what you're saying. If I had a multiband transceiver, & wanted to make my own dipole, then I could keep it simple at first by justing making one for the longest wavelength (40) meter. The, if that works, add some gadgetry for isolating a portion of the dipole (traps)?
That kit dual-band kit from Pacific Antennas that Dave was talking about is cheap enough, only $25. According to the PDF it seems rather easy to put together with minimal tools. Except I might need an SWR.
Plenty of options!
Mark
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
David,
I appreciate the suggestion. It seems I have much studying to do before I decide what I'm going to do for an antenna. Making my own seems to be a reasonable idea.
From what I've seen so far, it can be done with simple tools. Plus it would be nice to know how to put one together with a roll of wire, just in case. Peter Parker says fences, railings, & even bridges can be used!
Mark
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
Go to tractor supply and pick up a spool of galvanized electric fence wire, 17ga. You get a 1/4 mile spool for under $20. You can also get 4" spacers to make your own feedline and a whole host of other things.
Vince.
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On 02/25/2018 12:48 PM, Michael Hagen wrote: A good source of wire for a dipole is to buy a 250 roll of #14 Stranded
at Home Depot or other building supply.
You can get it by the foot, but a much better deal to get the whole roll
Black or White.
Too start cut 2 - 34' pieces for 40M? You can use PVC pipe fittings to
make center and insulators (also Home Depot).
Don't fall for the copper coated steel wire sold as antenna wire. Yes
it is strong! I snaps up in a mess, trying to go
back in the roll. It is really hard to handle. If you must, it is just
Mig Welding wire, buy a roll at Harbor Freight.
It is cheap and will work.
73's
Mike, WA6ISP
On 2/25/2018 9:34 AM, Jerry Gaffke via Groups.Io wrote:
When we set up a single band wire dipole antenna, it needs to be cut
to the correct length.
This optimal length can vary based on wire diameter, insulation if
any, distance to other objects, ...
So it's usually cut a bit too long, and then "tuned" by measuring the
resonant frequency
and then judiciously trimming the ends a bit.
Though I got by when starting out (no swr meter or network analyzer)
with just a tape measure.
Once set up, you can drive the antenna from your rig without using a
"tuner",
which is a separate piece of gear to match the 50 ohm transceiver to
whatever the antenna happens to be.
Jerry, KE7ER
On Sun, Feb 25, 2018 at 09:15 am, Mark wrote:
I don't need to tune a piece of electrical wire for a single band.
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
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Michigan VHF Corp.
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Re: Raduino Replacemnt, COMING SOON!
Thanks for bringing this to my attention,
I will investigate and get back to you all on this.
73 NIck. VK4PLN.
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
Hi Rich,
Thanks for the suggestion. Yes, I've heard that before. They don't necessarily need to be clipped. They can just be bent? More information for my antenna book. Great!
Mark
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
Thanks again for the information, Jerry. :)
So I would need a tuner. Even if I don't make my own rig, knowing about antennas seems rather critical.
Right now I'm checking out Peter Parker's books, 99 Things You Can Do with Amateur Radio, & Minimum QRP. After that I'm going to have a look at his, Hand-carried QRP Antennas, book, as well as the, Understanding Antennas For The Non-Technical Ham, book available at hamuniverse.com.
thanks,
Mark
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Re: Looking for Completely Functional Dual-Band 20/(17/15/10/6) Meter QRP Rig with SSB/PSK
#bitx20help
I have had wonderful luck with homemade coax traps. There are some formulas on the Internet and I found them extremely accurate with RG 58 coax. ?
To tune them, put them in series between a signal source and a RF detector, such as the field strength detector of a SWR meter old fashion type.
If you set the output power really really low, you could use a ubit X as the Signal source.
On Feb 25, 2018, at 15:46, Jerry Gaffke via Groups.Io < jgaffke@...> wrote:
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With all that said about the EFHW's, I agree with David that building a 40/20 dipole
with traps is a good solution.? Especially if not interested in spending $140.
I'd start with a straight 40 meter dipole, get some use out of it before?adding the traps.
The traps will require some careful measurements with appropriate gear to get right.?
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Hi Biz
no, I don't think so. ?I think the Universal II is an alternative pattern of case for the Bitx40. ? The slot for the display is different from the original Universal I, ? and that's about it.
I'm waiting ?for the uBitx cases to come out, too! ? Come on Sunil, getcha finger out!
Norm vk5gi
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Re: Schematic Drawing Software
?I haven't really looked at them closer as to which ones have more complete libraries, etc.? Some are used along with their own pcb services and all.? I'd hate to start with one and have to change around.? But anyway be nice if someone did a thorough review.? Oh well.? Here is a list of ones I bookmarked for later.
?I wouldn't mind if anyone has experience with any of these to contact me directly.??? Anxious to see which ones work the best.? I know part of it depends if you're going to do pcb designs as well.??? I've got a list of a few of those services as well.
73, Michael
KM4OLT
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Re: Broadcast band interference, uBitx
Howard; I think Glenn is right.
If you have a very strong signal nearby, metal shielding will
help but not eliminate the problem.
You need a better bandpass filter between the antenna and the rig, or some filter
which will eliminate low frequencies, or a notch filter to take out your particular
interfering frequency. The easiest to do is a high pass filter which will attenuate
frequencies below about 2 MHz. If the signal is very strong, both a HPF and
a notch filter are in order.
There has been some discussion of filters for BCI on this list (and other lists).
Search here first.
Also look for the work of Joe Carr. He was a RF engineer very interested in
BCI and designed many filters for all kinds of situations.
john
AD5YE
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N8DAH
Mark K0ABD
Nick VK4PP
Michael Monteith