In my experience, most EMI is common mode, and is not accurately described on data sheets. but here, I'm not looking at EMI - I'm concerned about differential mode transients (inductive things like r
On 5/13/21 2:01 PM, Doug Ronald wrote: It seems like a Maxim MAX16171 would fit the bill. It handles an input protection range of -42 through +76 V, and with an external FET, any reasonable current y
On 5/13/21 3:08 PM, tony.kaz-- via TowerTalk wrote: It is time to get rid of my 50+ year old Heathkit oil paint can dummy load.I want to mount a 1500W (intermittent) dummy load vertically on my groun
On 5/22/21 8:42 AM, k7lxc-- via TowerTalk wrote: Sorry, but I don't believe any of that.? It sounds purely anecdotal. Anecdotal?!? Ha - most of the stuff you get here is anecdotal along with lo
Been chasing down noise sources in my own home for starters and some of the charging wall warts and LED under cabinet supplies are amazing noise generators. I also have a new $2500 refrigerator that
A 15 minute session with EZNEC, and a candidate yagi design, is plenty adequate for showing that theres some serious systems engineering involved in coming up with the right set of trade-offs, starti
I'm trying to build my first Off-Center Fed Dipole for 40-10M. I'm following the directions at If you're looking for multiband, then a "fan dipole" is probably a better bet - it's symmetrical, just n
On 6/3/21 5:32 PM, Bill via TowerTalk wrote: After lots of BS and wrangling, it appears I will probably get a permit for my tower in Belize. That's the good news. The bad news is that although I a
On 6/3/21 5:59 PM, Lux, Jim wrote: On 6/3/21 5:32 PM, Bill via TowerTalk wrote: After lots of BS and wrangling, it appears I will probably get a permit for my tower in Belize. That's the good news.
Don't rule out uneducated, and reactionary imbeciles, either... We had a 199.9' tower put in the community. Met all requirements. Local short term political attention whores (neighbors getting "ele
On 6/16/21 8:33 AM, jim.thom jim.thom@telus.net wrote: On a side note, N3RR, Bill Hider, a few yrs ago, bought 700 (seven hundred) of the type 31, 2.4 inch OD cores...from I think, Fair rite..... and
All that data went into a spreadsheet, with data points at limits of 160, 80, and 40M bands, centered in 20 and 15, and at around 28.5 MHz, and for each winding (turns, winding material), worst case
I'd have to look at the spreadsheets -- it's been three years. But because resonances are involved, f the parameters I measured, Rs, Xs, and Zmag at a given frequency for a 10-turn winding, almost 2:
Yes. Another rabbit hole. :) Jim _____________ This is why at work, I do the initial calculation to see if it's doable at all, and then let someone who actually knows about magnetics actually do the
On 6/16/21 4:07 PM, Jim Brown wrote: On 6/16/2021 2:39 PM, Dan Maguire wrote: I never found an actual datasheet for Amidon type 31. A link to a page showing the u'/u'' plots, not just physical dimen
Just posted by Roy Lewallen, W7EL: https://eznec.com/retirement.htm In that retirement page, Roy mentions a known bug in NEC4.2. Does anyone have more information on that? "At the time of this writin
The rev history here: https://www.eznec.com/Updates50.html doesn't mention it. There are a few issues with variable definitions in COMMON blocks (documented on W7AY's site), and the use of Intel Sp
I need to electrically and mechanically join 2 perpendicular pieces of bare, #12 copper wire. They will be subject to wind forces which have repeatedly broken mere solder joints. Suggestions ? As wis
I have 8 radials. Each radial is insulated from the tower. The radials must then be connected to each other with a ring around the tower. This connection between the ring and each radial is where I h
I don't understand these suggestions. Steve asked about perpendicular connections, not inline, and using split bolts means that one or both of the soft copper wires is going to be under buffeting t