Ham Community | wa3ltj | Activity https://ham.community/members/wa3ltj/activity/ Activity feed for wa3ltj. Fri, 01 May 2026 00:28:37 +0000 https://buddypress.org/?v=2.21.0 en-US 30 hourly 2 21dfd57470ca235c6f07c3e681a2d582 wa3ltj replied to the discussion Actual SWR of an antenna in the forum Theory & experiments https://ham.community/forums/discussion/actual-swr-of-an-antenna/#post-22486 Mon, 28 Jul 2025 20:08:56 +0000 Reply to Actual SWR of an antenna

Here is easiest way to do the calculation

]]> 3575e748615c6bf9e4155fe489e65551 wa3ltj started the discussion Actual SWR of an antenna in the forum Theory & experiments https://ham.community/forums/discussion/actual-swr-of-an-antenna/ Mon, 28 Jul 2025 19:06:03 +0000 Actual SWR of an antenna

Determine the VSWR of antenna A using the parameters F, X, N, L and defined here.
The electrical arrangement is: Transmitter with CW signal at frequency F (MHz). The transmitter is connected to a VSWR meter. The VSWR value is the radio N:1.0. The other side of the SWR meter is connected to coaxial cable of length X (feet). The coax cable has…

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]]> 32e30694c309b75dd91364803dbb8411 wa3ltj answered to question Interpreting an unknown signal seen at 147.18MHz https://ham.community/content-feed/p/868/ Tue, 27 May 2025 22:00:07 +0000 Re: Interpreting an unknown signal seen at 147.18MHz
I like Jim’s answer, but you might try inserting a step attenuator in between the SDR and the antenna. That way you can gradually reduce the outside signals.  There are a few kits, or you can study…

]]> 0 2fb0ad408874827b247d146f58f67076 wa3ltj answered to question Placement of antenna transmission line https://ham.community/content-feed/p/665/ Tue, 03 Sep 2024 11:17:25 +0000 Re: Placement of antenna transmission line
I mostly agree with Jim’s comments, but whether the possible ill effects matter depends on some details. Cable type, parameters. For example, RG8x vs LMR400 vs RG-174 Highest frequency of oper…

]]> 0 4fdf0c6655da52f82cccc108b378f8b1 wa3ltj replied to the discussion FT-DX10 power meter in the forum Yaesu group discussions https://ham.community/groups/yaesu-group/forum/discussion/ft-dx10-power-meter/#post-22258 Wed, 14 Aug 2024 17:44:29 +0000 Reply to FT-DX10 power meter

Sorry I did not see this sooner. I was not a member of the group until now.
The FTdx10 has a number of idiosyncrasies associated with SSB. The major problem is adjusting the mic gain, processing gain, and the AMC (automatic microphone control). These interact and just increasing the mic gain will not increase power depending on the other…

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]]> cfb75bb8a3f5b4c2d4a159b6cfb1dede wa3ltj answered to question Intentionally stalling a stepper motor https://ham.community/content-feed/p/644/ Thu, 08 Aug 2024 19:46:50 +0000 Re: Intentionally stalling a stepper motor
After reading. Stepping motors do not stall, they skip.  The motor current goes up as the load goes up. Also, a stepper motor will skip more often at higher speeds. The current and skip depend on t…

]]> 0 e36f5b2caa035f5bfac85629eeb70981 wa3ltj answered to question How can I measure the rotational force needed to adjust a vacuum variable capacitor? https://ham.community/content-feed/p/643/ Thu, 08 Aug 2024 19:39:42 +0000 Re: How can I measure the rotational force needed to adjust a vacuum variable capacitor?
I 3D printed a calibrated, counterweighted arm. I hung a plastic bag and filled it with quarters until the shaft of the vacuum capacitor reliably moved. At 40 quarters the arm rotates reliably. The…

]]> 0 99031e2da7d5d9d15a892c4b1bf0b0d4 wa3ltj posted a new question to Ask the Elmers https://ham.community/content-feed/p/640/ Fri, 02 Aug 2024 12:28:37 +0000 Intentionally stalling a stepper motor
I am building a loop antenna using a vacuum variable capacitor adjusted by a stepper motor. I want to find the limit of the capacitor screw range. That would be a calibration zero point for adjusti…

]]> 0 bc2407a536ff6b2a0e5b1a9efa2cdc22 wa3ltj commented on a question https://ham.community/content-feed/p/610/ Tue, 09 Jul 2024 12:31:04 +0000 I entered my question into chatGPT. It wants me to use a torque wrench or torque screwdriver, which I don’t have. It recommends a flexible coupling. Bad idea for measuring a torque. I will …

]]> 0 9e0ae4201bd0a3e41573bbb38a1ad886 wa3ltj posted a new question to Ask the Elmers https://ham.community/content-feed/p/605/ Wed, 03 Jul 2024 16:20:29 +0000 How can I measure the rotational force needed to adjust a vacuum variable capacitor?
I just ordered a vacuum variable capacitor to continue my experiments with loop antennas. This one is decent quality, U.S. made, used capacitor. I was wondering if there was a relatively simple, ye…

]]> 0 80aa7802c6bc55b60e356161e6ddd81b wa3ltj commented on an answer https://ham.community/content-feed/p/604/ Wed, 03 Jul 2024 16:13:44 +0000 Perhaps you can use WSPR to compare the two antennas. There is actually special hardware and software for this, but you might be able to get some idea with less formal testing.

]]> 0 ace3b5c4083d683cd104b157db41e227 wa3ltj answered to question Are these radials or counterpoises at the base of an attic Vertical? https://ham.community/content-feed/p/600/ Tue, 02 Jul 2024 20:43:23 +0000 Re: Are these radials or counterpoises at the base of an attic Vertical?
Because the antenna is far from the Earth (no capacitive coupling to the Earth) and because the “radials” are resonate, I would argue that the horizontal wires in the attic are elevated radials. Se…

]]> 0 56367fa1c883554838bf97a0583cef09 wa3ltj replied to the discussion PC headset to ICOM 7600 connector in the forum ICOM group discussions https://ham.community/groups/icom-group/forum/discussion/pc-headset-to-icom-7600-connector/#post-22078 Wed, 06 Mar 2024 02:06:37 +0000 Reply to PC headset to ICOM 7600 connector

Yes. There was a typo. Corrected to: “diagram for wiring a PC headset” I am not looking for pin-outs of connectors. Lacking a diagram, I will work from the pin-outs and make (and test) my own diagram.

Where do I find a correct diagram for wiring a PC headset (2 separate stereo 3.5mm plugs) to the microphone jack of an Icom 7600?

]]> 2fe9cc200324cc2e886df5d3eff701da wa3ltj reached the posting rank 5W: Rank 2/14 https://ham.community/content-feed/p/484/ Wed, 06 Mar 2024 02:06:37 +0000
5W posting rank

Rank 2/14

]]> 0 d651c11c97be06ff6bc4b4d0372d068d wa3ltj started the discussion PC headset to ICOM 7600 connector in the forum ICOM group discussions https://ham.community/groups/icom-group/forum/discussion/pc-headset-to-icom-7600-connector/ Tue, 05 Mar 2024 19:50:55 +0000 PC headset to ICOM 7600 connector

Where do I find a correct diagram from wiring a PC headset (2 separate stereo 3.5mm plugs) to the microphone jack of an Icom 7600?

]]> 43ab4fa93590e37f3017539e1db6bf6e wa3ltj replied to the discussion Who needs an audio interface? in the forum Digital group discussions https://ham.community/groups/digital-group/forum/discussion/who-needs-an-audio-interface/#post-21879 Tue, 06 Feb 2024 03:25:07 +0000 Reply to Who needs an audio interface?

Is there any else to consider? That’s all.

]]> 17806d17e8d0ea162e3687e760d0df8f wa3ltj started the discussion Who needs an audio interface? in the forum Digital group discussions https://ham.community/groups/digital-group/forum/discussion/who-needs-an-audio-interface/ Mon, 05 Feb 2024 00:12:03 +0000 Who needs an audio interface?

I like to operate POTA and sometimes use an FT-891 mobile rig. The FT-891 has a USB CAT control. I use a cable from the PC to the rig. However, the rig does not have a built-in audio card interface. For modes like FT8, the manual says you can connect the audio signals in the rear of the radio directly to a sound card. I use an audio USB…

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]]> 91a1b8045572a71a9b0322a6a01bcfa1 wa3ltj replied to the discussion Many hobbies in one in the forum Anything Ham & Comms https://ham.community/forums/discussion/many-hobbies-in-one/#post-21825 Fri, 02 Feb 2024 17:38:55 +0000 Reply to Many hobbies in one

Antique radio collecting and restoration

Having something to occupy your time while your girlfriend runs mountain trails.

]]> 679052948376cdfc4c8bf7c02a97d194 WA3LTJ earned the earned award Bronze Group Award: Joining groups fosters collaboration and, as you know, […] https://ham.community/content-feed/p/268/ Tue, 09 Jan 2024 15:56:11 +0000

Joining groups fosters collaboration and, as you know, Ham Community is about collaboration | contribution | camaraderie. Earning the Bronze Group Award should be fairly easy, you just need one!

]]> 0 5641103e1d0d6c0f23f30d2c724b7b0f WA3LTJ earned the nominated award Elmer: Becoming a Ham Community Elmer is an achievement in and […] https://ham.community/content-feed/p/267/ Tue, 09 Jan 2024 15:55:03 +0000

Becoming a Ham Community Elmer is an achievement in and of itself. Operators are admitted into The Elmers’ Circle when they demonstrate a thorough understanding of one – or possibly several – aspects of Amateur Radio. Elmer admission and good standing is discussed and decided within The Elmers’ Circle. In addition to the prerequisites which…

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