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Locked LZ1AQ choke and feeder length questions please.
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13 January 2022
I bought an LZ1AQ active antenna amplifier to try. The performance of my Wellbrook wide aperture loop has been excellent since moving it further from the house, so I would like to try a loop as far from my house and other prorties as possible. What is the maximum realistic length of CAT5e cable I can run please? It will be suspended above head height off trees in a big wood. As a maybe very nueve aside questiomn, can such a signal be "boosted As for a choke or pair of chokes for the CAT5e, my main interests are the amateur bands at LF, MF and 160 meters. What would people recommend as a ferrite material to use? Many thanks -- Best regards, Chris mailto:chris@... |
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On Thu, Jan 13, 2022 at 12:11 PM, Chris Wilson wrote:
What is the maximum realistic length of CAT5e cable I can run please? It will be suspended above head height off trees in a big wood. As a maybe very nueve aside questiomn, can such a signal be "boostedA 30m (100ft) length of Cat 5 has typically 3 dB of attenuation at 30MHz, 2dB at 10MHz and <1dB at 1MHz. If your receiver noise floor rises by >6dB when the antenna is connected, you won't have a problem. 20 turns on an FT240-31 core for 160m & 80m. Try type 77 material for lower frequencies, but you would need about 40 turns for the 300-500KHz NDB band which is not really practical. Regards, Martin |
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Best person to ask is LZ1AQ. Great guy and always responds. I have about a 50 foot run and it works fine. I have no?choke on it.? Mike AB4KJ On Thu, Jan 13, 2022 at 6:12 AM Chris Wilson <chris@...> wrote: 13 January 2022 |
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On Thu, Jan 13, 2022 at 03:07 PM, Simon wrote:
On the ground would be better..Maybe, but in woodland it's likely to get chewed by various animals, unless you run it in some hose pipe or similar protection. Even if it is a few feet up in the sky, squirrels will be tempted to have a go at it. Regards, Martin |
¿ªÔÆÌåÓýFrom my experience as a former cellphone base station engineer in Southern England, I found that the most common culprits in rural sites were small woodmice. They even managed to get inside the cabins occasionally and could be found happily nesting in the cable trays. Ian Brooks, Verwood, Dorset, UK. On 13/01/2022 15:51, Martin via
groups.io wrote:
On Thu, Jan 13, 2022 at 03:07 PM, Simon wrote: |
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Cable protection or even burying in gnd via suitable conduit is good..stops the bloody foxes here in London..( fcukers are everywhere!)
Saying on gnd or below because qro transmissions will ingress said cable if close/ up high/ or cable length just happens to be 1/4w or multiples of.. Ask how i know!! I ran my rx loop cables fence height at first..easy..now in/ on gnd. ( not easy) MASSIVE difference in cm pickup and opps cables re radiating rf.( causing all sorts of grief.) lesson learned. Cable protection sleeving comes in 25m rolls, cheap, easy to use.( corrigated slit stuff¡spelt that wrong.) used in automotive industry mainly on hgv¡¯s ( trucks) really good strong stuff, wears out metal if rubbing it. Gives the foxes a good run for their money! Not lost another cable.. Why the hell do foxes want to eat cables and antenna support ropes??? Simon g0zen |
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Thanks for all the replies everyone.
I was hoping for more like 75 or more yards, are such things as line amplifiers available for such long runs? If I could get the loop or vertical dipole 75 yards from the radio I would be a reasonable distance from all properties nearby. I could get much further but the cable run would start to be Beverage (sp?) like. As to chokes the blurb on the LZ1AQ web site suggests winding several turns of internal wire from CAT5e cable, each conductor pairing having their own windings. He shows a small toroid used for these multiple windings. I reckon using a 230 sized toroid you could get a lot of turns on. He also says to ground the shield with as short a lead as possible, meaning the toroid has to be at ground level, near the antenna, and possibly another at ground level nearest the shack end. The choke advice seems more geared to using a small vertical dipole than a loop, but also he infers the dipole is superior at LF / MF. Tell me about rodent damage! I have repaired enough vehicle wiring looms where rats and mice have done thousands of pounds worth of damage to cars wiring. The damned things even have their favourite insulation types! I reckon an enterprising fella' could sell bits of insulated loom wire as mouse trap bait... ;) We have outdoor aviaries here so grain is always about, which means rats, squirrels and mice are never far away outside, but burying the feeder in heavy woodland would make a real mess, and probably destabilise some trees. We lost a load in the last wind storm. Having seen the noise reduction just moving the loop 50 feet or so I am keen to see if I can't do better still (either I'm never satisfied or I'm striving for continual improvements, not sure how you'd describe it!) Thanks again 2E0ILY |
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Rodent damage, well, it is a real problem where I live. Midwest and next to a forest preserve. Every year between fall through winter I lose several RG6 cable?runs from rodents gnawing on the cable. In some cases they cut right through it. I use the self sealing RG6 but it doesn't?help when they chew the cable repeatedly. My runs are between 50 to 200 feet. My only recourse has been to have a ready supply of RG6 connectors and splices and extra cable. They seem to prefer the coax to the power control cables, but I have had them damage the power and control cables. With regard to the length of the cable and pick up issues, I usually do buy the ferrite cores and put them on the line at both ends of the run; and at the antenna end and one before entrance into the shack. On Fri, Jan 14, 2022 at 3:07 AM Chris Wilson <chris@...> wrote: Thanks for all the replies everyone. |
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Hello Mike,
Thursday, January 13, 2022 Thanks Mike, meanwhile I have some surplus 15mm copper plumbing pipe so intend making a loop, or pair of loops, from this using eight 45 degree Yorkshire type soldered fittings per loop to make near circles. It appears a large loop conductor diameter is favorable. Best regards, Chris mailto:chris@... MI> Best person to ask is LZ1AQ. Great guy and always responds. I MI> have about a 50 foot run and it works fine. I have no choke on it. MI> Mike MI> AB4KJ MI> On Thu, Jan 13, 2022 at 6:12 AM Chris Wilson <chris@...> wrote: MI> 13 January 2022 MI> MI> MI> I bought an LZ1AQ active antenna amplifier to try. The MI> performance of my Wellbrook wide aperture loop has been excellent MI> since moving it further from the house, so I would like to try a MI> loop as far from my house and other prorties as possible. What is MI> the maximum realistic length of CAT5e cable I can run please? It MI> will be suspended above head height off trees in a big wood. As a MI> maybe very nueve aside questiomn, can such a signal be "boosted MI> MI> As for a choke or pair of chokes for the CAT5e, my main MI> interests are the amateur bands at LF, MF and 160 meters. What MI> would people recommend as a ferrite material to use? MI> MI> Many thanks MI> MI> MI> MI> -- MI> MI> MI> Best regards, MI> Chris mailto:chris@... MI> MI> MI> MI> MI> MI> MI> MI> |
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Mike,
I have lots RG-6 out in the woods for RX antennas. I also have gotten loads of cable chewed up. One thing I have started to do is use dead fall to cover the lines. Branches, small trees...it helped a lot didn't eliminate the problem but did help. I also just moved some coax? several feet and that sometimes helped. Good luck and 73 Fred KB4QZH |
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Automotive cable sheving( spelt that wrong ( sheving))
It is corrugated,split ( so easy to fit around cables) comes in long lengths, is cheap.is silly strong( ie will rub though steel given the chance) Comes in different diameters¡rodent proof.. Its used on hgv¡¯s ( big trucks if in USA.) to protect the safety critical wiring/ pipe stuff. Worth a try..??? Simon g0zen Ps foxes have attacked it here, but can not chew though it..you can tell they have been at it, but thats all.( they soon give up, get bored??) Having said that maybe USA rodents are more mean than UK rodents..?? |
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Fred, you could try some animal psychology too. Scatter tasty bait on different tracks away from cables and something unpleasant near your cable runs.
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A bit softer that automatic weapons on motion sensors... -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Simon Sent: 19 January 2022 20:06 To: [email protected] Subject: Re: [loopantennas] LZ1AQ choke and feeder length questions please. Automotive cable sheving( spelt that wrong ( sheving)) It is corrugated,split ( so easy to fit around cables) comes in long lengths, is cheap.is silly strong( ie will rub though steel given the chance) Comes in different diameters¡rodent proof.. Its used on hgv¡¯s ( big trucks if in USA.) to protect the safety critical wiring/ pipe stuff. Worth a try..??? Simon g0zen Ps foxes have attacked it here, but can not chew though it..you can tell they have been at it, but thats all.( they soon give up, get bored??) Having said that maybe USA rodents are more mean than UK rodents..?? |
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Here's what I'm dealing with... photo links below.
There's a creek that run in the area the closer I run cables to it the more I get chewed up. The most wanted list of critters here are Squirrels,Groundhogs,Skunks,Coyote,Muskrat,Fox. The Groundhogs are the worse they do a lot of damage I have taken out a very high number but it does nothing to the population. 73 Fred KB4QZH |
¿ªÔÆÌåÓýApart from Simon¡¯s suggestion I don¡¯t know what else to say, Fred. Steel pipes? We¡¯re very lucky the UK isn¡¯t crawling with groundhogs, skunks, coyote or muskrat. No doubt someone will post a list of UK vermin I¡¯m simply not aware of. I¡¯ll have a new loop in the garden this time next month and the cables will be exposed so I think I¡¯ll take some precautionary action. ? Tom G6PZZ ? From: [email protected] <[email protected]>
On Behalf Of Fred
Sent: 20 January 2022 16:01 To: [email protected] Subject: Re: [loopantennas] LZ1AQ choke and feeder length questions please. ? Here's what I'm dealing with... photo links below. |
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Hi Tom,
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You Brits don't have any critters left because you eat them all.
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Everett N4CY
In a message dated 1/20/2022 10:32:56 AM Central Standard Time, tom@... writes: ?
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On Thu, Jan 20, 2022 at 04:32 PM, Tom Crosbie G6PZZ wrote:
We¡¯re very lucky the UK isn¡¯t crawling with groundhogs, skunks, coyote or muskrat.Agreed, but we still have squirrels, rabbits, rats, badgers & deer. Even crows can be problematic. Rabbits will quite happily chew through anything that looks like grass or plant roots, and for some reason they seem to favour coax that also carrys DC. The squirrels managed to gnaw through the fuel pipes on one car on two separate occasions until the garage fitted some steel mesh, and for some reason the crows took a dislike to the rear bumper, which they kept on having a real go at until we covered it up. Regards, Martin |
Ian Brooks
Everett N4CY
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