Today I was working a digital mode (FT8) and lost connection to the radio. I
cycled power with no success. On reseating the USB connection at the computer I felt the ferrite core was HOT. The cable didn't feel hot at all. I'm using a 20m hamstick in the office as my antenna. I shut everything down to cool off. Afterwards everything seems to be working correctly. Any ideas? Tnx and 73 Jerry D. Moore AE4PB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
With your antenna that close, are you sure you're not exceeding human
body RF exposure requirements? 73 Frank W3LPL ----- Original Message ----- From: [hidden email] To: [hidden email] Sent: Sunday, April 19, 2020 12:46:55 AM Subject: [Elecraft] USB Noise core gets hot when operating FT*? Today I was working a digital mode (FT8) and lost connection to the radio. I cycled power with no success. On reseating the USB connection at the computer I felt the ferrite core was HOT. The cable didn't feel hot at all. I'm using a 20m hamstick in the office as my antenna. I shut everything down to cool off. Afterwards everything seems to be working correctly. Any ideas? Tnx and 73 Jerry D. Moore AE4PB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
I’m not sure, but, it’s a good point. I’m only running 50Watts.
From: [hidden email] <[hidden email]> Sent: Monday, April 20, 2020 1:36 PM To: [hidden email] Cc: [hidden email] Subject: Re: [Elecraft] USB Noise core gets hot when operating FT*? With your antenna that close, are you sure you're not exceeding human body RF exposure requirements? 73 Frank W3LPL _____ From: [hidden email] <mailto:[hidden email]> To: [hidden email] <mailto:[hidden email]> Sent: Sunday, April 19, 2020 12:46:55 AM Subject: [Elecraft] USB Noise core gets hot when operating FT*? Today I was working a digital mode (FT8) and lost connection to the radio. I cycled power with no success. On reseating the USB connection at the computer I felt the ferrite core was HOT. The cable didn't feel hot at all. I'm using a 20m hamstick in the office as my antenna. I shut everything down to cool off. Afterwards everything seems to be working correctly. Any ideas? Tnx and 73 Jerry D. Moore AE4PB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] <mailto:[hidden email]> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
You're safe, but obviously your K3 isn't...
----- Original Message ----- From: [hidden email] To: [hidden email], [hidden email] Cc: [hidden email] Sent: Monday, April 20, 2020 5:40:26 PM Subject: RE: [Elecraft] USB Noise core gets hot when operating FT*? I’m not sure, but, it’s a good point. I’m only running 50Watts. From: [hidden email] <[hidden email]> Sent: Monday, April 20, 2020 1:36 PM To: [hidden email] Cc: [hidden email] Subject: Re: [Elecraft] USB Noise core gets hot when operating FT*? With your antenna that close, are you sure you're not exceeding human body RF exposure requirements? 73 Frank W3LPL ----- Original Message ----- From: [hidden email] To: [hidden email] Sent: Sunday, April 19, 2020 12:46:55 AM Subject: [Elecraft] USB Noise core gets hot when operating FT*? Today I was working a digital mode (FT8) and lost connection to the radio. I cycled power with no success. On reseating the USB connection at the computer I felt the ferrite core was HOT. The cable didn't feel hot at all. I'm using a 20m hamstick in the office as my antenna. I shut everything down to cool off. Afterwards everything seems to be working correctly. Any ideas? Tnx and 73 Jerry D. Moore AE4PB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by ae4pb
Definitely
You can prove it to yourself by connecting a dummy load to your K3 73 Frank W3LPL ----- Original Message ----- From: [hidden email] To: [hidden email], [hidden email] Sent: Monday, April 20, 2020 5:52:57 PM Subject: RE: [Elecraft] USB Noise core gets hot when operating FT*? Are you saying that’s what’s causing the ferrite core on the USB cable to heat up? Jerry Moore Cell: 803-431-1870 From: [hidden email] <[hidden email]> Sent: Monday, April 20, 2020 1:52 PM To: [hidden email] Subject: Re: [Elecraft] USB Noise core gets hot when operating FT*? You're safe, but obviously your K3 isn't... ----- Original Message ----- From: [hidden email] To: [hidden email] , [hidden email] Cc: [hidden email] Sent: Monday, April 20, 2020 5:40:26 PM Subject: RE: [Elecraft] USB Noise core gets hot when operating FT*? I’m not sure, but, it’s a good point. I’m only running 50Watts. From: [hidden email] < [hidden email] > Sent: Monday, April 20, 2020 1:36 PM To: [hidden email] Cc: [hidden email] Subject: Re: [Elecraft] USB Noise core gets hot when operating FT*? With your antenna that close, are you sure you're not exceeding human body RF exposure requirements? 73 Frank W3LPL From: [hidden email] To: [hidden email] Sent: Sunday, April 19, 2020 12:46:55 AM Subject: [Elecraft] USB Noise core gets hot when operating FT*? Today I was working a digital mode (FT8) and lost connection to the radio. I cycled power with no success. On reseating the USB connection at the computer I felt the ferrite core was HOT. The cable didn't feel hot at all. I'm using a 20m hamstick in the office as my antenna. I shut everything down to cool off. Afterwards everything seems to be working correctly. Any ideas? Tnx and 73 Jerry D. Moore AE4PB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by ae4pb
On 4/18/2020 5:46 PM, [hidden email] wrote:
> I felt the ferrite core was HOT. The cable didn't feel hot at all. > I'm using a 20m hamstick in the office as my antenna. That's an "un-natural act" -- the antenna is not designed for that application, and, among other things, requires a good connection to the chassis of a vehicle or something similar to act as a counterpoise. Without a counterpoise, the coax acts as a radial. At the very least, you should provide radials to act as a counterpoise. There are thousands of ferrite parts, all of them very different from each other. Exactly WHICH "ferrite core" are you using (part number, mfr, mix), where is it in the system? Are multiple turns wound through it? 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Hi, Jim. I think he was talking about the ferrite core embedded in the USB cable. Check the title of his post. But for sure, his setup is a really poor one. 73, Dave AB7E On 4/20/2020 11:33 AM, Jim Brown wrote: > On 4/18/2020 5:46 PM, [hidden email] wrote: >> I felt the ferrite core was HOT. The cable didn't feel hot at all. >> I'm using a 20m hamstick in the office as my antenna. > > That's an "un-natural act" -- the antenna is not designed for that > application, and, among other things, requires a good connection to > the chassis of a vehicle or something similar to act as a > counterpoise. Without a counterpoise, the coax acts as a radial. At > the very least, you should provide radials to act as a counterpoise. > > There are thousands of ferrite parts, all of them very different from > each other. Exactly WHICH "ferrite core" are you using (part number, > mfr, mix), where is it in the system? Are multiple turns wound through > it? > > 73, Jim K9YC > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by ae4pb
Jerry,
Ignoring how you've set up your station for the moment (every station has compromises but some push that to an extreme); the shutdown of the connection is likely that RF got into the USB cable (as demonstrated by the hot ferrite) which caused the USB port hardware to lock up. USB hardware can 'stick' so it won't work properly, a complete power cycle empties it of any charge, 'unsticking' the hardware. (Yah a gross simplification, but you get the point.) The only SURE way to restore it to function (assuming it's not blown) is a complete power down (unplugged from all power, let the power supply drain, disconnect the laptop battery, count another ten seconds) and restart. That is why it worked after you 'cooled it off'. If you can shift to a real serial port (not a serial dongle), that will help. USB is RF intolerant compared to serial. It's simplest to avoid USB as much as feasible near any RF. If you can't avoid USB, you'll need to add a lot more ferrite or better yet, improve the antenna situation dramatically. In the cases I MUST run a USB connection, I distance the antenna from the computer as much as possible and I run <100 watts (QRP to me), but generally that's when I run a portable station. Jim, K9YC will tell you it's related to 'Pin 1' and the short version is that is has to do with bonding all things to a common ground; USB devices often ignore this. In a few cases, improved bonding between the computer and radio /may/ help, but I'd have low hopes if the antenna is mere feet away. Take the hot ferrite as a warning sign, it's not a healthy environment. 73, Rick NK7I On 4/18/2020 5:46 PM, [hidden email] wrote: > Today I was working a digital mode (FT8) and lost connection to the radio. I > cycled power with no success. On reseating the USB connection at the > computer I felt the ferrite core was HOT. The cable didn't feel hot at all. > I'm using a 20m hamstick in the office as my antenna. I shut everything down > to cool off. Afterwards everything seems to be working correctly. > > Any ideas? > > Tnx and 73 > > Jerry D. Moore > > AE4PB > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
It really sounds from the posts as if the radio and everything connected to
it was acting as counterpoise to the ham-stick. This is dangerous because it means your radio is acting as part of the antenna. You don't want to touch antennas while they are transmitting, especially at higher power. The RF choke on the USB cable was doing its job to try to protect the computer from stray RF. If the radio is acting as part of the antenna then a lot of power is going to be heading down that USB cable (a USB-Cable-Counterpoise) and the choke will be absorbing it (or some of it) before it hits the computer. The choke has become hot because it's absorbing that RF energy. Current is flowing through it for it to get warm, so some energy will still be reaching the computer. It implies that a fair amount of your 50W may not be getting into the air at all but getting into equipment and anything touching or connected to it. - Richard On Mon, 20 Apr 2020 at 20:59, Rick Bates, NK7I <[hidden email]> wrote: > Jerry, > > Ignoring how you've set up your station for the moment (every station > has compromises but some push that to an extreme); the shutdown of the > connection is likely that RF got into the USB cable (as demonstrated by > the hot ferrite) which caused the USB port hardware to lock up. > > USB hardware can 'stick' so it won't work properly, a complete power > cycle empties it of any charge, 'unsticking' the hardware. (Yah a gross > simplification, but you get the point.) > > The only SURE way to restore it to function (assuming it's not blown) is > a complete power down (unplugged from all power, let the power supply > drain, disconnect the laptop battery, count another ten seconds) and > restart. That is why it worked after you 'cooled it off'. > > If you can shift to a real serial port (not a serial dongle), that will > help. USB is RF intolerant compared to serial. It's simplest to avoid > USB as much as feasible near any RF. > > If you can't avoid USB, you'll need to add a lot more ferrite or better > yet, improve the antenna situation dramatically. > > In the cases I MUST run a USB connection, I distance the antenna from > the computer as much as possible and I run <100 watts (QRP to me), but > generally that's when I run a portable station. Jim, K9YC will tell you > it's related to 'Pin 1' and the short version is that is has to do with > bonding all things to a common ground; USB devices often ignore this. > > In a few cases, improved bonding between the computer and radio /may/ > help, but I'd have low hopes if the antenna is mere feet away. Take the > hot ferrite as a warning sign, it's not a healthy environment. > > 73, > Rick NK7I > > > On 4/18/2020 5:46 PM, [hidden email] wrote: > > Today I was working a digital mode (FT8) and lost connection to the > radio. I > > cycled power with no success. On reseating the USB connection at the > > computer I felt the ferrite core was HOT. The cable didn't feel hot at > all. > > I'm using a 20m hamstick in the office as my antenna. I shut everything > down > > to cool off. Afterwards everything seems to be working correctly. > > > > Any ideas? > > > > Tnx and 73 > > > > Jerry D. Moore > > > > AE4PB > > > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[hidden email] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to [hidden email] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
You could try setting up counterpoises for the ham-stick. If it's for the
20m band, then ra few adial wires about 5m long should help. Connect to the earth side at the base of the ham-stick. They're 1/4 wavelength so if tuned correctly will act as a low impedance to the RF energy at the base of the antenna providing what some call a "virtual earth". They effectively form the bottom half of the dipole antenna. You'd want to protect your equipment. Another part of this equation would be to stop RF going back down the outside of the coax to the radio. If you don't have a choke ferrite to work with make a coil with the coax. Inductance increases with diameter and amount of turns. Also lower power. If you do the above then your antenna will be working more efficiently anyway and you may find that you're doing well on 10W or less as well as being safer. I got UK to USA on 10W on 20m this weekend using Morse Code. Antenna was bigger which helps, though it was a dipole who's main radiation pattern would have been more North/South (just the way our garden is oreinted) not East/West. - Richard On Tue, 21 Apr 2020 at 10:14, Richard Corfield <[hidden email]> wrote: > It really sounds from the posts as if the radio and everything connected > to it was acting as counterpoise to the ham-stick. This is dangerous > because it means your radio is acting as part of the antenna. You don't > want to touch antennas while they are transmitting, especially at higher > power. > > The RF choke on the USB cable was doing its job to try to protect the > computer from stray RF. If the radio is acting as part of the antenna then > a lot of power is going to be heading down that USB cable (a > USB-Cable-Counterpoise) and the choke will be absorbing it (or some of it) > before it hits the computer. The choke has become hot because it's > absorbing that RF energy. Current is flowing through it for it to get warm, > so some energy will still be reaching the computer. > > It implies that a fair amount of your 50W may not be getting into the air > at all but getting into equipment and anything touching or connected to it. > > - Richard > > > On Mon, 20 Apr 2020 at 20:59, Rick Bates, NK7I <[hidden email]> > wrote: > >> Jerry, >> >> Ignoring how you've set up your station for the moment (every station >> has compromises but some push that to an extreme); the shutdown of the >> connection is likely that RF got into the USB cable (as demonstrated by >> the hot ferrite) which caused the USB port hardware to lock up. >> >> USB hardware can 'stick' so it won't work properly, a complete power >> cycle empties it of any charge, 'unsticking' the hardware. (Yah a gross >> simplification, but you get the point.) >> >> The only SURE way to restore it to function (assuming it's not blown) is >> a complete power down (unplugged from all power, let the power supply >> drain, disconnect the laptop battery, count another ten seconds) and >> restart. That is why it worked after you 'cooled it off'. >> >> If you can shift to a real serial port (not a serial dongle), that will >> help. USB is RF intolerant compared to serial. It's simplest to avoid >> USB as much as feasible near any RF. >> >> If you can't avoid USB, you'll need to add a lot more ferrite or better >> yet, improve the antenna situation dramatically. >> >> In the cases I MUST run a USB connection, I distance the antenna from >> the computer as much as possible and I run <100 watts (QRP to me), but >> generally that's when I run a portable station. Jim, K9YC will tell you >> it's related to 'Pin 1' and the short version is that is has to do with >> bonding all things to a common ground; USB devices often ignore this. >> >> In a few cases, improved bonding between the computer and radio /may/ >> help, but I'd have low hopes if the antenna is mere feet away. Take the >> hot ferrite as a warning sign, it's not a healthy environment. >> >> 73, >> Rick NK7I >> >> >> On 4/18/2020 5:46 PM, [hidden email] wrote: >> > Today I was working a digital mode (FT8) and lost connection to the >> radio. I >> > cycled power with no success. On reseating the USB connection at the >> > computer I felt the ferrite core was HOT. The cable didn't feel hot at >> all. >> > I'm using a 20m hamstick in the office as my antenna. I shut everything >> down >> > to cool off. Afterwards everything seems to be working correctly. >> > >> > Any ideas? >> > >> > Tnx and 73 >> > >> > Jerry D. Moore >> > >> > AE4PB >> > >> > ______________________________________________________________ >> > Elecraft mailing list >> > Home: http://mailman.qth.net/mailman/listinfo/elecraft >> > Help: http://mailman.qth.net/mmfaq.htm >> > Post: mailto:[hidden email] >> > >> > This list hosted by: http://www.qsl.net >> > Please help support this email list: http://www.qsl.net/donate.html >> > Message delivered to [hidden email] >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] > > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by ae4pb
Thanks Rick,
My Antenna situation is temporary. I purchased a Hustler 6BTV from DX Engineering am working on getting it installed. It may take several weeks as I work full time and am working towards my MBA full time. I may shuffle the project priorities around and work on the Coax routing to move my temporary antenna outdoors. Since it's a temporary setup I'll be routing out through the window which is going to take a bit of construction to achieve something that's secure and energy friendly. I'm not able to avoid using USB but I can certainly move the antenna. Jerry Moore AE4PB >Jerry, >Ignoring how you've set up your station for the moment (every station has compromises but some push that to an extreme); the shutdown? of the connection is likely that RF got into the USB cable (as demonstrated by the hot >ferrite) which caused the USB port hardware to lock up. >USB hardware can 'stick' so it won't work properly, a complete power cycle empties it of any charge, 'unsticking' the hardware.? (Yah a gross simplification, but you get the point.) >The only SURE way to restore it to function (assuming it's not blown) is a complete power down (unplugged from all power, let the power supply drain, disconnect the laptop battery, count another ten seconds) and restart.? That is >why it worked after you 'cooled it off'. >If you can shift to a real serial port (not a serial dongle), that will help.? USB is RF intolerant compared to serial.? It's simplest to avoid USB as much as feasible near any RF. >If you can't avoid USB, you'll need to add a lot more ferrite or better yet, improve the antenna situation dramatically. >In the cases I MUST run a USB connection, I distance the antenna from the computer as much as possible and I run <100 watts (QRP to me), but generally that's when I run a portable station.? Jim, K9YC will tell you it's related to 'Pin >1' and the short version is that is has to do with bonding all things to a common ground; USB devices often ignore this. >In a few cases, improved bonding between the computer and radio /may/ help, but I'd have low hopes if the antenna is mere feet away.? Take the hot ferrite as a warning sign, it's not a healthy environment. >73, >Rick NK7I ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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