On the comments about balun heating/QRO, even for guanella current baluns with lower loss cores like Type 61 or 43: I like this topic, because I've been wrestling with that issue for a 6:1 or 9:1 imp
Okay, here's my problem. I know I don't know this stuff. But I've tried to read everything I can find on the web. Including Jim K9YC's excellent amount of information at his website. But then I read
Looking at this document "Heat Dissipation in Electrical Enclosures" and a nice graph on heat dissipation vs total surface area for airtight enclosures, it would seem to me that: 1) assuming .1 db lo
at $110 for a single Tohtsu 3500, is that really a cost saving for this kind of outdoor switching? Just did a quick look, because my remembering of this is that most people who try to do a cheaper ho
I think David's lack of additional detail, plus focus on little stuff that doesn't matter so much, makes it sound dicier than it probably is. For instance, he says only 1.5' of the foundation is belo
I was thinking of the "One Man Tower" thing, not a crankup though. Apparently he has medical issues now though, no orders? India has an interesting situation. Only 10,000 hams in year 2000. Maybe 17,
James: I ran into this info just now that might help, or jostle memories. was this a guyed crankup? This page at K0RC's show the light weight T-354, which has the flat bars like you say. http://chude
oh man. I love this question! I use a Jet IWF-2000N hand winch that I bought as surplus relatively cheap (its new price is $700+), on a HG-70HD crankup. 1/4" cable. I've never heard of anyone else u
Jim K9YC mentioned google earth for getting terrain profiles. Here's a site that draws a terrain profile between two points. It uses a Google maps api. If I was a software guy, I'd know more about wh
Let's do numbers. If the winch and ginpole are at the pivot point of the tower, the analysis of forces is pretty simple. It's simple mechanics (think back to high school physics class). It's more com
Betonamit is one brand http://www.crowdersupply.com/betonamit.htm http://www.crowdersupply.com/Betonamit-MSDS.pdf Dexpan is another http://www.youtube.com/watch?v=Yfi0_5HIrmo&NR=1 http://www.archerus
I have a folded dipole up for 80m with a shorter coupled resonator (dipole) inside it to improve 2:1 SWR bandwidth to the full band. (so it looks like 3 wires) Fed with ladderline. 6:1 current balun
I would think a DC drill would give you the torque you want. I have/use a 24v Ridgid which I like for heavy duty drilling. spec says 615 in.lb for torque (I would think you wouldn't need more than 48
given -the weight of the tower -the length of the tower -the weight of anything else on the tower (winch, rotor, bearing, mast antenna) -the height of the pulley on the raising fixture -the attach po
This is a bit of a trick question, isn't it? Sure the pulling force, at any time, is less on the brake winch. That's why it's easier to turn it. But you also talked about braking and heat dissipation
when refurb'ing crankups, I always find the bronze sleeve bearings in the pulleys are worn and replace them. (along with the cables). People here have noted the problem with finding the right size to
Are you in charge of the pour yourself? I'm not a concrete guy, but I think a conversation with your readymix supplier would help. I think you've got some other issues to ponder. Looking at the weath
re: the strength of the attach point on tilting up a 1400 lb tower: Art/Clint, Saying 1000 lbs is max force is very wrong, right? That all said, a 5/16" bolt can be fine. I would use grade 5 or 8. I'
By tiltup do you mean a full sized tower? I may have misunderstood the question, but: No, I'm talking about the typical 21' compressed crankup, (1400 lbs in this case), lying horizontal, with two bol
256 lbs? pretty light. I'll throw my 2 cents in . Interested in whether these numbers align with people's experiences. (people must be using some numbers in their heads when they do this stuff?) Be n