We are on grand kid babysitting duty which limits the day.? I might make it out later in the afternoon to the Baylands and am planning to go to the FARS meeting. Dick K6PBF
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On 4/23/2025 4:45 PM, Hiroki Kato wrote: I plan to be at the Baylands starting with lunch followed by ops.
Hiroki AH6CY
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I am dying to see you all again, but after a nasty eye infection kept me down for nearly two months, I rolled my ankle this week!? Six x-rays today, and I'll be down again for a while.
I'll be there in spirit.? Have fun! 73, Eric NF6S
ex WD6DBM
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On Wed, Apr 23, 2025 at 4:45 PM, Hiroki Kato <hiroki@...> wrote: I plan to be at the Baylands starting with lunch followed by ops.
Hiroki AH6CY
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I plan to be at the Baylands starting with lunch followed by ops.
Hiroki AH6CY
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David,
One of the common causes of SWR's sudden change while seemingly everything appears to be correctly connected is a faulty connection inside the PL259. I have had this problem more than once in the past. I know you say you tried different coax cables. But just in case, try to open up the PL259 and see they are alright.
Hiroki AH6CY
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On Apr 21, 2025, at 9:36 AM, Cliff Sojourner K6CLS via < cls@...> wrote:
Hi David,
I bet the change in swr is from the telescoping antenna.? The untelescoped (retracted) sections make poor to intermittent contact as it rattles in the wind.? I have done this before ;)
Pull out each section just a little bit, so they are grabbed - feel the friction of the crimp at the end of the enclosing section - then adjust as desired for length.
That little red cylinder looks like like it is just an SO239 to 3/8" x 24 adapter.? Dual, one side for the coax braid, one side for the coax center.? Can you check its connections with your VOM?
Cliff K6CLS On April 21, 2025 1:36:37 AM PDT, "David via ?" < dkvarn@...> wrote: Antennas, that is, my name (trademark pending) for the popular (at least among our group) simple vertical antenna kits. I have a couple of related questions (see at bottom) but will first provide some background.?These are advertised as 14-30 MHz 1/4 wave, 16.4 ft. length of both stainless telescoping whip and counterpoise (see pix). Strangely, they are advertised as QRP but rated 300W. I bought mine via Amazon, and it arrived in time for me to try it out at Baylands Friday (report below). An OK deal IMO at about $44 (much less on AliExpress?et al., but I didn't want to touch them for reasons discussed). Mine came in a plastic bag; jealous of Dave C.'s unit, which came in a nice cardboard box. ? Intending to operate 10M, I extended the whip and counterpoise to about half length, elevated the counterpoise with help from a cooperative plant. ~1.6 VSWR at about 25 MHz. This allowed the '703 autotuner to converge on 10M, though with plenty of exercise for the tuner relays. 10M was hot--S. America and VK-land boomed in, however they would strangely cut in and out. The MFJ 259b similarly showed the VSWR suddenly going from 1.6 to >10:1. Tightened connections, no change. Substituted coax, no change. Repeated several times and it seemed to settle down. Managed to work Chile, and though it was with some difficulty and I got a 5/1, I was happy. No other contacts, though I heard British Virgin Is. on 12M; on to the bike tour (WX was beautiful). Got home, checked the coax and the red barrel and counterpoise connections, all of which seemed OK.? ? Questions: * Any owners tried disassembling the red barrel? I'd like to do so for a visual, but don't want to break it.? * Can anybody recommend some type of inexpensive transport case, maybe a music instrument case? You can get an idea of the size from the pic. I think a flute case would be too small. ? Thanks, and best, --David KM6RI
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There was a article a few months ago pointing out that stainless steel is a terrible material for antennas.
The DC resistance is much higher than copper or aluminum. The magnetic properties significantly reduce the skin depth making the total losses much higher than other metals.
That said, most portable antennas use stainless and talk up the mechanical ruggedness but don't compare electrical performance with similar antenna made from other metals.
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Hi David,
I bet the change in swr is from the telescoping antenna.? The untelescoped (retracted) sections make poor to intermittent contact as it rattles in the wind.? I have done this before ;)
Pull out each section just a little bit, so they are grabbed - feel the friction of the crimp at the end of the enclosing section - then adjust as desired for length.
That little red cylinder looks like like it is just an SO239 to 3/8" x 24 adapter.? Dual, one side for the coax braid, one side for the coax center.? Can you check its connections with your VOM?
Cliff K6CLS
On April 21, 2025 1:36:37 AM PDT, "David via groups.io" <dkvarn@...> wrote:
Antennas, that is, my name (trademark pending) for the popular (at least among our group) simple vertical antenna kits. I have a couple of related questions (see at bottom) but will first provide some background.?These are advertised as 14-30 MHz 1/4 wave, 16.4 ft. length of both stainless telescoping whip and counterpoise (see pix). Strangely, they are advertised as QRP but rated 300W. I bought mine via Amazon, and it arrived in time for me to try it out at Baylands Friday (report below). An OK deal IMO at about $44 (much less on AliExpress et al., but I didn't want to touch them for reasons discussed). Mine came in a plastic bag; jealous of Dave C.'s unit, which came in a nice cardboard box.
?
Intending to operate 10M, I extended the whip and counterpoise to about half length, elevated the counterpoise with help from a cooperative plant. ~1.6 VSWR at about 25 MHz. This allowed the '703 autotuner to converge on 10M, though with plenty of exercise for the tuner relays. 10M was hot--S. America and VK-land boomed in, however they would strangely cut in and out. The MFJ 259b similarly showed the VSWR suddenly going from 1.6 to >10:1. Tightened connections, no change. Substituted coax, no change. Repeated several times and it seemed to settle down. Managed to work Chile, and though it was with some difficulty and I got a 5/1, I was happy. No other contacts, though I heard British Virgin Is. on 12M; on to the bike tour (WX was beautiful). Got home, checked the coax and the red barrel and counterpoise connections, all of which seemed OK.?
?
Questions:
* Any owners tried disassembling the red barrel? I'd like to do so for a visual, but don't want to break it.?
* Can anybody recommend some type of inexpensive transport case, maybe a music instrument case? You can get an idea of the size from the pic. I think a flute case would be too small.
?
Thanks, and best, --David KM6RI
|
Antennas, that is, my name (trademark pending) for the popular (at least among our group) simple vertical antenna kits. I have a couple of related questions (see at bottom) but will first provide some background.?These are advertised as 14-30 MHz 1/4 wave, 16.4 ft. length of both stainless telescoping whip and counterpoise (see pix). Strangely, they are advertised as QRP but rated 300W. I bought mine via Amazon, and it arrived in time for me to try it out at Baylands Friday (report below). An OK deal IMO at about $44 (much less on AliExpress et al., but I didn't want to touch them for reasons discussed). Mine came in a plastic bag; jealous of Dave C.'s unit, which came in a nice cardboard box.
?
Intending to operate 10M, I extended the whip and counterpoise to about half length, elevated the counterpoise with help from a cooperative plant. ~1.6 VSWR at about 25 MHz. This allowed the '703 autotuner to converge on 10M, though with plenty of exercise for the tuner relays. 10M was hot--S. America and VK-land boomed in, however they would strangely cut in and out. The MFJ 259b similarly showed the VSWR suddenly going from 1.6 to >10:1. Tightened connections, no change. Substituted coax, no change. Repeated several times and it seemed to settle down. Managed to work Chile, and though it was with some difficulty and I got a 5/1, I was happy. No other contacts, though I heard British Virgin Is. on 12M; on to the bike tour (WX was beautiful). Got home, checked the coax and the red barrel and counterpoise connections, all of which seemed OK.?
?
Questions:
* Any owners tried disassembling the red barrel? I'd like to do so for a visual, but don't want to break it.?
* Can anybody recommend some type of inexpensive transport case, maybe a music instrument case? You can get an idea of the size from the pic. I think a flute case would be too small.
?
Thanks, and best, --David KM6RI
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Hiroki looks to me like you will have a nice group of supporters at your talk in Pacificon.? ?The pressure is on, better bring your A game.? Seriously,? it's nice to hear that so many from this group will be there.? Thanks, Doug?
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Re: How many on this list are planning on coming to Pacificon?
I will be there!
On Saturday, April 19th, 2025 at 3:01 PM, Peter Wanger - WA6ECH via groups.io <PKWanger@...> wrote:
I usually attend all three days.
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? Pete? WA6ECH
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Connie KN2EFI
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Re: How many on this list are planning on coming to Pacificon?
I usually attend all three days.
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? Pete? WA6ECH
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Re: How many on this list are planning on coming to Pacificon?
I¡¯m planning on attending.
Joy
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Re: How many on this list are planning on coming to Pacificon?
Super.? Thanks Ron for your support?
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Re: How many on this list are planning on coming to Pacificon?
I'll probably attend Friday and Saturday, same as I did last year. ?But I'll be commuting, so not sure how late I'll stay.
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Ron
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How many on this list are planning on coming to Pacificon?
I would like to know how many on this list are planning on coming to Pacificon and supporting Hiroki during his talk?? Plus there are 5 more qrp talks including Carol Milazzo.? And we will have our usual fun activities Friday and Saturday nights,? plus the opportunity to buy a 2025 updated version of the original Norcal 40 kit at a very low cost.
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All the details are on the CalQrp groups.io website.
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Doug
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I plan on coming out.
Dick K6PBF
On 4/17/2025 1:15 PM, David via
groups.io wrote:
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Anybody up for radio bonding? WX should be beautiful. Best,
--David KM6RI
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Anybody up for radio bonding? WX should be beautiful. Best, --David KM6RI
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Re: zBitx Transceiver does it all
There's yet a third issue with the zBitx: It's likely that RF digital noise is getting coupled into the receiver, raising the noise floor and reducing SNR, as well as creating serious hum from the speaker audio out.
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I'm guessing that there's a decent, maybe 50/50, chance that all 3 issues are fixable.
But these might not be quick fixes.
1. Some insulated copper foil shielding under the display and maybe between PCBs might help with the internal RFI. ?Perhaps more bypass caps might be needed as well.
2. Additional bypass caps and a different drive level or output coupling for the Si5351 clock chip might reduce the 2 MHz spurs to under legal limits.
3. And junking the current rat's nest of layers of sample processing + keying code, and replacing it with CW specific sample processing routine running on a priority thread locked to a cpu core, plus slightly better interrupt handling, or perhaps an even simpler fix, should fix the CW keying latency.
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*IF* these issues are fixable, the zBitx *might* become a nice little remote+local operable portable QRP SDR rig.
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I plan on waiting to see if others who are more experienced with these bitx designs can fix some of these issues before I spend more time digging in myself.
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But if you want a working radio out-of-the-box, you might want to wait for version 2 or 3 of the hardware. ?
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IMHO. YMMV, 73, Ron, n6ywu
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Re: zBitx Transceiver does it all
That does it for me.? I am returning my zbitx unopened as soon as it arrives.? ?How disappointing this whole episode has been.? ?Now I will find out how good they are about refunds.? Thaks for your help and expertise.? Doug
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Re: zBitx Transceiver does it all
Before putting your zbitx on the air, I recommend checking its transmit spectrum for purity.
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I just rechecked the spectrum of my unit on 20M and 40M with an 2nd tinySA Ultra, and ?still see some nasty non-harmonic spurs outside the ham bands, at around 35-40 dBc. ?Don't know yet whether it's just my unit, maybe something like an incorrect bias setting, or a product design flaw. ?Hopefully fixable.
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- Ron
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Re: zBitx Transceiver does it all
I would not make any assumptions about external keyer input working until some proper software fixes have been implemented and properly tested.
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The last update was not it. ?It appears that other outside software developers had to step in and fix his last project. We may need to wait for the same thing to happen with the zbitx.
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I still have hope for the basic concept. ?But it's currently a project, not a product.
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- Ron
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Cliff Sojourner K6CLS
David
Peter Wanger - WA6ECH