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Re: Balun vs no balun
Bob: It'll be interesting to follow your R&D. I screwed up in an earlier post. I had matching transformers on the brain and what I described with 1-10mH was for a receiver headend bandpass amplifier. I was laughing (out loud)... how could you wind a 10mH choke with 16 or 14 gauge wire. It would weigh somewhere over 22 pounds. Now, try to hang that from your center insulator.? It's easy to forget that receiving and transmitting aren't always reciprocal. Keep the spirit, Bob, of experimenting, building, testing - just be careful with high places, hot soldering irons and linear amplifier plate voltages. bb,kpr
Engineering, where enigma meets paradox
On Friday, September 20, 2024 at 04:08:34 PM EDT, Bob Doolittle W1CTC <w1ctc@...> wrote:
It's a cheap balun. I'm going to get a better one and see what the difference is. It does seem to have less noise.
73 Bob w1ctc
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Re: Balun vs no balun
NOTE: The values I quoted are for a band-specific transformer and regardless of the ratio, IE; 4:1, 9:1, etc. That can be determined by the secondary ratio (T1/T2^2) For noise abatement I prefer a coax choke. They are very good for multi-band. My 160 thru10 endfed uses 10-12 turns, 8" dia, 50 Ohm coax. The beauty of that is a choke is virtually lossless and some baluns ain't so good. A non-optimal balun can be a real power pig. bb
Engineering, where enigma meets paradox
On Friday, September 20, 2024 at 07:31:28 AM EDT, Bob, N1KPR via groups.io <rwbetts@...> wrote:
Bob, something is mis-applied. The balun seems to be self-resonant at 3825 or so. The fact that both upper and lower freqs are attenuated will be one or both of the following: 1. Not enough ferrite in the core, or 2. Not enough windings. If you can access the coil and measure its reactance, then it can be recalculated to work properly. For 80 meters the choke should be at least 500mH, but safer would be 10mH. 10mH at 3MHz is safe for the 80M band and good down to below 2MHz. Curious, is the balun an autoformer (series windings), or common ground, or two separate windings with no internal connection? bb,kpr
Engineering, where enigma meets paradox
On Friday, September 20, 2024 at 03:27:56 AM EDT, Jay Gulick K1FJG <jwgulick1@...> wrote:
Very Interesting Bob. ?Great info. ?Thank you for this. ?Flying back to the US tomorrow. ?See you next Saturday. Jay Gulick On Sep 20, 2024, at 12:10?AM, Bob Doolittle W1CTC via groups.io <w1ctc@...> wrote:
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Diversity
Diversity phasing can be used 2 ways; 1. cancel local noise. 2. Steer the reception lobe(s). Linrad takes a bit of getting used to, but if you already own an
SDR Play Duo, then the SDR Uno software has the diversity option already
built in.
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Regards,
Engineering, where enigma meets paradox |
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Re: Balun vs no balun
Bob, something is mis-applied. The balun seems to be self-resonant at 3825 or so. The fact that both upper and lower freqs are attenuated will be one or both of the following: 1. Not enough ferrite in the core, or 2. Not enough windings. If you can access the coil and measure its reactance, then it can be recalculated to work properly. For 80 meters the choke should be at least 500mH, but safer would be 10mH. 10mH at 3MHz is safe for the 80M band and good down to below 2MHz. Curious, is the balun an autoformer (series windings), or common ground, or two separate windings with no internal connection? bb,kpr
Engineering, where enigma meets paradox
On Friday, September 20, 2024 at 03:27:56 AM EDT, Jay Gulick K1FJG <jwgulick1@...> wrote:
Very Interesting Bob. ?Great info. ?Thank you for this. ?Flying back to the US tomorrow. ?See you next Saturday. Jay Gulick On Sep 20, 2024, at 12:10?AM, Bob Doolittle W1CTC via groups.io <w1ctc@...> wrote:
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Re: Fw: Announcement: Boy Scouts JOTA (Oct 19,2024)
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-------- Original message -------- From: "Bob, N1KPR via groups.io" <rwbetts@...> Date: 9/18/24 11:43 AM (GMT-05:00) To: W1ORS IO <[email protected]> Subject: [w1ors] Fw: Announcement: Boy Scouts JOTA (Oct 19,2024) Engineering, where enigma meets paradox ----- Forwarded Message -----
From: Douglas Sharafanowich <ctjotaham@...> To: "w1ors@..." <w1ors@...> Sent: Wednesday, September 18, 2024 at 11:09:44 AM EDT Subject: Fwd: Announcement: Boy Scouts JOTA (Oct 19,2024) Good morning! Please distribute to Club members ASAP. Thank you. 73, Douglas WA1SFH ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SHARE "THE MAGIC" OF AMATEUR RADIO Amateur Radio enriches the lives of everyone that it touches. Boy Scouts Jamboree On The Air (JOTA) 2024...?is COMING! Saturday - Oct 19 LINK: ? ? The Clock is Ticking... In just about?1 month, you will have the opportunity to?introduce kids?to Amateur Radio and start them on the?first step?to being licensed. - ?This is a?fun and rewarding?Public Service Event (PSE) - ?It also is a great excuse to?"Go Portable", and field test your gear. ? WE NEED?YOU! YOU?Make it Happen! Status (9/17/24): - ?I have?confirmed requests?for JOTA Activity Stations at?TWO?Boy Scout Camps?(Greenwich and Goshen). and - ?I am waiting to hear back to hear back about?two additional camps?(Redding and New Hartford). ? SHARE THE MAGIC Give the Scouts the opportunity to have conversations On-The-Air. We NEED YOU... and your equipment. I am looking to form Teams of 4-6 hams to go to each camp, run a JOTA "Activity Station", and provide: - ?HF radios - ?VHF/UHF Mobile Radios - ?Appropriate antennas and support gear NOTE: AC Power is not always available. ? Got Questions? Please contact me at: To Volunteer,?please go to: Thank you ! 73, Douglas Sharafanowich - WA1SFH ARRL - CT Section Youth Coordinator (Troop 701 - Milford, CT) cell: 203-494-3885 email: ctjotaham@... |
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Fw: Announcement: Boy Scouts JOTA (Oct 19,2024)
Engineering, where enigma meets paradox ----- Forwarded Message ----- From: Douglas Sharafanowich <ctjotaham@...> To: "w1ors@..." <w1ors@...> Sent: Wednesday, September 18, 2024 at 11:09:44 AM EDT Subject: Fwd: Announcement: Boy Scouts JOTA (Oct 19,2024) Good morning! Please distribute to Club members ASAP. Thank you. 73, Douglas WA1SFH ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SHARE "THE MAGIC" OF AMATEUR RADIO Amateur Radio enriches the lives of everyone that it touches. Boy Scouts Jamboree On The Air (JOTA) 2024...?is COMING! Saturday - Oct 19 LINK: ? ? The Clock is Ticking... In just about?1 month, you will have the opportunity to?introduce kids?to Amateur Radio and start them on the?first step?to being licensed. - ?This is a?fun and rewarding?Public Service Event (PSE) - ?It also is a great excuse to?"Go Portable", and field test your gear. ? WE NEED?YOU! YOU?Make it Happen! Status (9/17/24): - ?I have?confirmed requests?for JOTA Activity Stations at?TWO?Boy Scout Camps?(Greenwich and Goshen). and - ?I am waiting to hear back to hear back about?two additional camps?(Redding and New Hartford). ? SHARE THE MAGIC Give the Scouts the opportunity to have conversations On-The-Air. We NEED YOU... and your equipment. I am looking to form Teams of 4-6 hams to go to each camp, run a JOTA "Activity Station", and provide: - ?HF radios - ?VHF/UHF Mobile Radios - ?Appropriate antennas and support gear NOTE: AC Power is not always available. ? Got Questions? Please contact me at: To Volunteer,?please go to: Thank you ! 73, Douglas Sharafanowich - WA1SFH ARRL - CT Section Youth Coordinator (Troop 701 - Milford, CT) cell: 203-494-3885 email: ctjotaham@... |
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Re: KE8SPB - K1TMW Alan G. Thorpe Scholarship Receipient for 2024
That is great news. I can't wait to see her "letter of Appreciation" which the League asks them to send. I'm sending this as a reminder that some of the things that SARC has done are ethereal, un-seeable, untouchable, yet they can mean so much to someone or a group of someones. In my 33-years at SARC, I feel this is one of the best decisions we've made. I know that you and Dave (W1CTN) and myself had a few conversations concerning the rather large investment. But, I have always thought that one of our most valuable possessions is something that is totally intangible; "knowledge." When I think back to the very early days of all the teachers,friend guys and gals that inspired me to learn, I can appreciate the small help that SARC has done. I also think about the young'ns that I met three decades ago in Boothe Park and where they are now, in adult life. The three basic precepts of Amateur Radio is "promote the hobby", "investigate new technologies" and "education: helping people to grow in the hobby through knowledge and understanding." I also remember all those past years that seem like a very fast trip through time; like watching your twins and all the progress and successes that they learned and earned. Just a parallel in seeing my daughter grow from single-digit age through the systems of education and then her successes and good fortune today. Thanks to you and Dave inspiring me to allocate the funds from Al, K1TMW. Bob, N1KPR
Engineering, where enigma meets paradox
On Saturday, September 14, 2024 at 02:42:35 PM EDT, Adam Hosa via groups.io <ifone@...> wrote:
Thanks for sharing bob! On Sep 14, 2024, at 2:30?PM, Bob Giuliani W1RPG via groups.io <rpgiuliani@...> wrote:
It's nice to see that the ARRL has this year included the Alan G. Thorpe Memorial Scholarship, K1TMW after being left out in 2023. I see the recipient is a future biomedical student and has been active in the hobby. <20240914_142011.jpg> Thank you, Robert (Bob) Giuliani. W1RPG? U <20240914_142011.jpg> |
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Re: KE8SPB - K1TMW Alan G. Thorpe Scholarship Receipient for 2024
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On Sep 14, 2024, at 2:30?PM, Bob Giuliani W1RPG via groups.io <rpgiuliani@...> wrote:
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KE8SPB - K1TMW Alan G. Thorpe Scholarship Receipient for 2024
开云体育It's nice to see that the ARRL has this year included the Alan G. Thorpe Memorial Scholarship, K1TMW after being left out in 2023. I see the recipient is a future biomedical student and has been active in the hobby. Thank you, Robert (Bob) Giuliani. W1RPG? U |
Bob, N1KPR
Bob Doolittle W1CTC
Bob Giuliani W1RPG
Adam Hosa
