I will bring it to Pacificon and give it to her to try.? I think it will help.? I listened today.? ?Tuned to 40 meter Ft8 frequency,? loud stations.? Inserted filter, nothing heard.? Took it out, found a loud? ssb signal, Inserted filter.? Signal gone, nothing.? ?Same result on 30 and 17 meters.? Then, with the filter in, tuned 20 meter band.? Lots of signals.? I? think my tests are valid, and verify that the filter works.? The true test will been when Joy tries it at Baylands.?
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I think it looks ok! Can see the insertion loss, a few dB. A little ripple, so 3 element circuit? Not too steep, so I wonder if it would help for Joy's use, which I think was filter other signals in band? But I'm no expert.
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On October 11, 2024 2:36:24 PM PDT, Doug Hendricks <ki6ds1@...> wrote: This shows marker at 14.650.? Cliff, how does it look?
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This shows marker at 14.650.? Cliff, how does it look?
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Here is my first attempt at building a bandpass filter for 20 meters.? How does it look.
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6m on fire SA won't make lunch
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If you look at the tiny low pass filters (toroids plus capacitors) on the circuit board of your uSDX or QDX, that's the size of filtering you need for QRP bandpass filters for 10M or bandstop filters for 20M. ?Both should easily fit in a mint tin. ?Bigger filters are for power handling of RF from QRO transmitters and amps, in use or being used nearby. ?73, Ron, N6YWU
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Doug, yes the most I run is 10 W and usually less. I hear interference, mostly from CW stations. I'm not sure if they are on the same band that I am on or not. It seems to me it bleeds to some of the other bands. I thought a band pass filter may solve the problem. I have never used one before, but this is how I think they work. If they are on 20 and I am on 10, ?I could have a band pass filter for 10 and that would stop the interference from 20? Is this correct? The band pass filter I was talking about isn't really expensive. I think it was in the $60 range.?
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Joy
N6GO
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Dave, Do you mean the cafe at noon and ops at about 1:30pm? I think those are the normal times. I am planning on coming to both.
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Joy
N6GO
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I will not be there today. I have out of town guests. See you (at least some of you) at Pacificon next week.
Hiroki AH6CY
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On Oct 11, 2024, at 02:11, David via groups.io <dkvarn@...> wrote:
? Planning to join y'all for lunch, ops and bike. Best, --David KM6RI
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Planning to join y'all for lunch, ops and bike. Best, --David KM6RI
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I'll be entertaining my favorite kindergartner while her mom goes
to the first parent/teacher conference.? There is a small chance
I'll get out to the ops afterwards.? If not, next week.
Dick
On 10/10/2024 5:36 PM, David W Crocker
via groups.io wrote:
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I plan to be at the Bay Cafe
for lunch and ops at the Baylands around 1:30
Dave W6VYC
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I plan to be at the Bay Cafe for lunch and ops at the Baylands around 1:30
Dave W6VYC
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Re: IC 7300 Clock Battery
Thanks Dave, I don't think the clock in my 7300 has ever been correct. Thanks for passing this fix on. I will forward to my engineering department, my husband.?
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Joy
N6GO
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Very? interesting postings.? But are we using a cannon to kill a fly?? These filters are all good and do the job I am sure.? But they are expensive,? and handle hundreds of? Watts.
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Joy runs qrp. A KX2 I believe,? and she is running? 10 W at the most.? I don't think I have ever seen anyone out at Baylands who wasn't running qrp. Correct me if I? am wrong.? So we have one qrp station on 20 meters who wants to avoid interference from? other stations on other bands who are also running qrp.? Why does she need a filter that will hand hundreds of Watts and is very expensive?
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One of the things that attracted me to qrp was that you don't need a lot of money for equipment? ((at least you didn't? before Elecraft came on the scene) and I love and have their gear).
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It's easy to build a band pass filter in an altoids tin.? Hiroki how about you and I build one and see how it works.? ?Build it and test it empirically.? ?Is the challenge accepted?? The rest of you are welcome to try too.
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I love this group because they actually do ham radio.
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Doug
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How many of us have a 7300 with the clock battery run down and time constantly needs setting.
Here is a nice solution by installing a rechargeable battery LR 2032 and a 1K resistor.
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This is the original source of the S Tuner design that was in the FARS homebrew contest. The unit at FARS was nicely built in a non-conductive wooden/plexiglass box. He claimed this tuner architecture was more efficient than the Palsar tuner.
Dave W6VYC
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Christopher,
Nice looking products with very good adjacent band rejection. The low power toroid versions are reasonably priced.
Dave W6VYC
On Monday, October 7, 2024 at 01:47:12 PM PDT, Christopher AI6KG <ch@...> wrote:
We (AB6RF and me) have been pretty happy with K6WX's filters and diplexers at Pacificon.? ? We rarely run more than 500W on any station (due to AC power limitations).? They run cool; we have never plugged in the fans.
VA6AM also has some good designs as well.? ? We have used some of these too at the station.
73 de AI6KG
These are the bandpass filters that have been used for years. Don't know if you can find them anymore. They are coupled resonator type filters using air core inductors. If you really want, you can make your own. See attached.
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We (AB6RF and me) have been pretty happy with K6WX's filters and diplexers at Pacificon.? ? We rarely run more than 500W on any station (due to AC power limitations).? They run cool; we have never plugged in the fans.
VA6AM also has some good designs as well.? ? We have used some of these too at the station.
73 de AI6KG
These are the bandpass filters that have been used for years. Don't know if you can find them anymore. They are coupled resonator type filters using air core inductors. If you really want, you can make your own. See attached.
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Interesting article in the recent issue of of RadCom Plus which like QEX.
Dave W6VYC
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If you have one built, let's put it in a VNA.? Either a nanoVNA, or my Rigol.? Cliff
On October 7, 2024 12:38:27 PM PDT, "David W Crocker via groups.io" <dwcae@...> wrote:
The values can be scaled by the ratio of the frequencies. ie: 21/28 for the multiplier for the inductors and capacitors to scale to 10 meters. if you want to see the response of various filters, use a program like Elsie. Take a look at the filters used by Rick and Joanna which are the one used by PAARA at Field Day and Pacificon.
Dave W6VYC
On Monday, October 7, 2024 at 11:43:22 AM PDT, Hiroki Kato <hiroki@...> wrote:
Dave,
Do you have any data in re how sharp/effective this filter is? I'd like to try building one (or more for other bands besides 21MHz).
Hiroki AH6CY On Oct 7, 2024, at 11:34 AM, David W Crocker via < dwcae@...> wrote: These are the bandpass filters that have been used for years. Don't know if you can find them anymore. They are coupled resonator type filters using air core inductors. If you really want, you can make your own. See attached.
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Cliff Sojourner K6CLS
David
David W Crocker