[TowerTalk] TowerTalk Digest, Vol 160, Issue 83
Wilson
infomet at embarqmail.com
Mon Apr 25 10:57:25 EDT 2016
Put a snatch block at the top and run a cable up and over.
Then the come a long can go vertical, outside, and be as long as it wants.
Come to think of it, don't most come a longs have a running pulley on the
cable, for double lining?
Then all you need is the lift point at the top.
WL
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Sent: Monday, April 25, 2016 10:41 AM
To: towertalk at contesting.com
Subject: TowerTalk Digest, Vol 160, Issue 83
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Today's Topics:
1. Re: [Bulk] Lifting a mast off the rotator (Don Moman VE6JY)
2. Rotor load bearing weight (Chuck Gooden)
3. RG-304 for CMC ? (Jim Thomson)
4. Re: RG-304 for CMC ? (Jim Brown)
5. Re: [Bulk] Lifting a mast off the rotator (Grant Saviers)
----------------------------------------------------------------------
Message: 1
Date: Mon, 25 Apr 2016 04:12:52 +0000
From: Don Moman VE6JY <ve6jy.1 at gmail.com>
To: "TOWERTALK at contesting. com" <TOWERTALK at contesting.com>
Subject: Re: [TowerTalk] [Bulk] Lifting a mast off the rotator
Message-ID:
<CAJf7ZhQD52=z_9EqkGBe22q6W4JbvNpZLQ-3kOzYgXOQpahDiw at mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
When space is at a premium and you don't have to move the load too far, a
turnbuckle is the answer.
73 Don
VE6JY
On Mon, Apr 25, 2016 at 3:05 AM, Grant Saviers <grants2 at pacbell.net> wrote:
> Les,
>
> IMO, the best idea is to attach a u-bolt with a hoist point bracket to the
> mast and use a come-along inside to the tower top plate, although
> come-alongs can be too long to fit. The shortest headroom lifters I've
> found is are 500# and 1000# capacity lever chain hoists, < 8". This is my
> strategy for a safe very heavy mast lift off the rotator, even if a foot
> or
> more of clearance is needed. A forged eye is fitted to a hole drilled in
> the top plate of the tower as an attachment point. Once installed, the
> attach points can be left for the "next time".
>
> Other ways to go: the die pry bar set from Harbor Freight and the 4 ton
> hydraulic frame straightener have been very handy for me to
> lift/separate/straighten things.
>
> #68339 or #1654 (the porta power from HF is now 2x the price from
> Amazon)
>
>
> http://www.amazon.com/Goplus%C2%AE-Porta-Power-Hydraulic-Repair/dp/B017H8R9E2/ref=sr_1_1?ie=UTF8&qid=1461551404&sr=8-1&keywords=hydraulic+frame+repair+kit
>
> the jaw separator might be useful for lifting once a pry bar gives some
> space for it, but needs a good purchase. Or use the small extension
> cylinder to a u-bolt fastened lift point above the tower top. Or use a
> small scissor jack, which I bought for taking apart rohn 25. The
> cylinders
> are also good for straightening bent tower parts.
>
> On a used 2800 I acquired the prior owner had secured a cut off box end
> wrench on the center bolt with a screw through the wrench handle and
> threaded into the Orion plate about 2" out from the bolt, oriented so the
> split mast clamp clears the wrench. Now I know why he did that.
>
> Grant KZ1W
>
>
> On 4/24/2016 19:11 PM, Les Kalmus wrote:
>
>> I came home from Visalia to find my antenna system freewheeling. The mast
>> holds 4 yagis, one of which is very large, and is rotated by an Orion
>> rotator.
>> If my suspicions are correct, the problem is the little 1/4" bolt holding
>> the shaft up into the bottom of the mast clamp has loosened and allowed
>> the
>> shaft to fall.
>>
>> The tower is lowered and the antennas are tied off to a tree. I have
>> removed the mast clamp and now I have to raise the mast about 1/2" to
>> free
>> the centering block so I can remove it to inspect that bolt.
>> I have a come along with an additional block with which I can lift the
>> mast, but the carabiner I have won't fit into the small space between the
>> centering block and the inside of the mast.
>>
>> Any suggestions on a way to either hook the mast from the bottom or to
>> clamp to it so I can raise it? We're talking maybe 400 lbs in the
>> complete
>> antenna system.
>> I have done this in the past but I think I didn't have the centering
>> block at that time so it was easier to get something hooked into the
>> bottom
>> of the shaft.
>>
>> Les W2LK
>>
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
> _______________________________________________
>
>
>
> _______________________________________________
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> http://lists.contesting.com/mailman/listinfo/towertalk
>
------------------------------
Message: 2
Date: Sun, 24 Apr 2016 23:30:36 -0500
From: Chuck Gooden <Chuck.Gooden at comcast.net>
To: towertalk at contesting.com
Subject: [TowerTalk] Rotor load bearing weight
Message-ID: <571D9D6C.3000602 at comcast.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
Should the rotor in a tower, bear the weight of the antennas and mast?
Or should the weight be on a bearing plate, and allow the rotor to be
easily removed?
What are the pros and cons of either approach?
Chuck Gooden N9QBT
------------------------------
Message: 3
Date: Sun, 24 Apr 2016 21:35:08 -0700
From: "Jim Thomson" <jim.thom at telus.net>
To: <towertalk at contesting.com>
Subject: [TowerTalk] RG-304 for CMC ?
Message-ID: <FDF5DA7A23164DED97D9FA3604D02E22 at JimPC>
Content-Type: text/plain; charset="UTF-8"
Date: Sun, 24 Apr 2016 17:14:14 -0400
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk at tm.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] RG-304 for CMC ?
What's the difference between using LMR-400, or BuryFlex with six 12"
dia Loops equally spaced, compared to bundling the same size loops into
a single bunch
or for that matter, grouping any coax together rather than equally
spaced loops?
It'd lower the resonant frequency, but other than that (and looking
neater), what about the choke's characteristics?
Would it narrow the range of high impedance? Lower, raise, or leave the
maximum impedance unaffected?
73
Roger (K8RI)
## Bunched up loops lowers res freq. Depending on choke config, it can
narrow the range of the choke, to the point where it covers 80m with high
5-6 k RS... but not 40m.
Lousy on 40m, like 650 ohms. This appears to be the case when Binoc
config is used in some cases. With binoc config, with torroids at the 9 +
3 oclock positions, the turns all end up bunched together for the entire
loops.
Bad news if LMR-400 /213-U /393 coax used. A LOT more C between turns
with the .405 OD cables...vs 58-U / 303 etc.
## One advantage to binoc config, is you can then wind in 1/2 turn
increments, like
4 - 4.5 ? 5 - 5.5 etc.
## 12 inch diam loops is a trick to maintain spacing between each loop.
With loops
equally spaced around the cores, now you end up with a mess that is almost 2
foot in diameter,
which is exactly what I dont want for a cmc...esp on a 80m rotary dipole,
mounted 10 ft up
the mast. 8.5 K in a little box, on 80m, with the CMC-230-5K is a more
elegant solution.
## 12 inch diam loop = 3 ft in circumference. 7 turns = 21 ft of
LMR-400..which is a lotta
weight,bulk,windload, etc. But it does provide outstanding high Z / RS
across 80+ 40m..and
160m.
Jim VE7RF
------------------------------
Message: 4
Date: Sun, 24 Apr 2016 22:44:40 -0700
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] RG-304 for CMC ?
Message-ID: <571DAEC8.6060704 at audiosystemsgroup.com>
Content-Type: text/plain; charset=utf-8; format=flowed
On Sun,4/24/2016 9:35 PM, Jim Thomson wrote:
> ## Bunched up loops lowers res freq.
Right.
> Depending on choke config, it can narrow the range of the choke,
Not if the core material is #31 or #43.
> to the point where it covers 80m with high 5-6 k RS... but not 40m.
> Lousy on 40m, like 650 ohms. This appears to be the case when Binoc
> config is used in some cases. With binoc config, with torroids at the 9
> +
> 3 oclock positions, the turns all end up bunched together for the entire
> loops.
> Bad news if LMR-400 /213-U /393 coax used. A LOT more C between
> turns
> with the .405 OD cables...vs 58-U / 303 etc.
This is nonsense.
>
> ## One advantage to binoc config, is you can then wind in 1/2 turn
> increments, like
> 4 - 4.5 ? 5 - 5.5 etc.
This is also nonsense. Chokes wound for the HF bands using #31 and #43
material have VERY low circuit Q, typically on the order of 0.4. This
makes them broad as a barndoor! Their tuning is NOT critical.
>
> ## 12 inch diam loops is a trick to maintain spacing between each loop.
> With loops
> equally spaced around the cores, now you end up with a mess that is almost
> 2 foot in diameter,
> which is exactly what I dont want for a cmc...esp on a 80m rotary dipole,
> mounted 10 ft up
> the mast. 8.5 K in a little box, on 80m, with the CMC-230-5K is a more
> elegant solution.
>
> ## 12 inch diam loop = 3 ft in circumference. 7 turns = 21 ft of
> LMR-400..which is a lotta
> weight,bulk,windload, etc. But it does provide outstanding high Z / RS
> across 80+ 40m..and
> 160m.
I don't know where you get this stuff, but it's nonsense.
73, Jim K9YC
------------------------------
Message: 5
Date: Mon, 25 Apr 2016 07:41:48 -0700
From: Grant Saviers <grants2 at pacbell.net>
To: Jim Thomson <jim.thom at telus.net>, towertalk at contesting.com
Subject: Re: [TowerTalk] [Bulk] Lifting a mast off the rotator
Message-ID: <571E2CAC.2030100 at pacbell.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
The used OR-2800 was driving a 3" mast, but I have one driving a 2"
without a centering block w/o problems (so far) but a bigger load is
going onto the 2" mast shortly.
Medium strength Loctite is a good idea if the internal threads can be
degreased. Instead of a split ring washer, I use Nord-Locks for
critical fasteners. Check out their video re locking fastener tests.
http://cdn.nord-lock.com/wp-content/uploads/2015/12/Nord-Lock-Junker-test-HD_1280x720.mp4
Grant KZ1W
On 4/24/2016 21:00 PM, Jim Thomson wrote:
> Date: Sun, 24 Apr 2016 20:05:13 -0700
> From: Grant Saviers <grants2 at pacbell.net>
> To: Les Kalmus <w2lk at bk-lk.com>, TOWERTALK at contesting.com
> Subject: Re: [TowerTalk] [Bulk] Lifting a mast off the rotator
> Les,
>
> On a used 2800 I acquired the prior owner had secured a cut off box end
> wrench on the center bolt with a screw through the wrench handle and
> threaded into the Orion plate about 2" out from the bolt, oriented so
> the split mast clamp clears the wrench. Now I know why he did that.
>
> Grant KZ1W
>
> ## slick idea, but it wont work if the optional m2 self centering 1/2
> inch thick,
> triangular chunk of AL is used. When the self centering device is use, a
> really
> long 1/4-20 SS bolt is provided.... to get from top of self centering
> block....
> all the way through the block, then to the threads in the steel base
> plate.
>
> ## I have 2 of the OR-2800 rotors.... and the self centering block is
> only required
> if a 2 inch mast is used. And even then, its really not required with
> a 2 inch mast.
>
> ## The self centering block is pyramid shaped, and the entire block
> fits inside a
> 2 inch mast. Dunno if it will still fit inside a 2 inch mast, that has a
> .375 wall thickness.
>
> ## If a 2 inch mast used, the clamp would normally be adjusted so its
> just a bit bigger
> than 2 inch. If 2 x thrust bearings are used, the self centering device
> is def not required.
>
> ## I would not use it. Instead use the shorter 1/4-20 bolt.... but
> use some blue loctite
> on the threads. Purple locite is slightly weaker than blue loctite..and
> will also work. Or at
> least use a SS split ring lockwasher on top of a SS fllatwasher, below
> the bolt head.
>
> ## the scissor jack is a good idea. The simple bottle jacks will also
> work, but have a limited
> amount of vertical lift distance. Cheap, and available from 1/2 to 20
> ton. The issue with bottle jacks is:
> you can precisely control the lifting function..... but when u go to let
> it down, it comes down quickly.
>
> Jim VE7RF
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
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