Interested in hearing if anyone has had success in gamma matching a standard
Rohn 45G foldover with a typical triband yagi on top to work on 80 and/or
160. If so, what approximate gamma configuration/dimensions and what extent
of radials were used?
Thanks to those who responded to my earlier request with 45G foldover
catalog pages.
Tnx/73 de Pete N5TP
--------------------------------------------------
From: <towertalk-request@contesting.com>
Sent: Sunday, March 21, 2010 8:30 AM
To: <towertalk@contesting.com>
Subject: TowerTalk Digest, Vol 87, Issue 67
> Send TowerTalk mailing list submissions to
> towertalk@contesting.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://lists.contesting.com/mailman/listinfo/towertalk
> or, via email, send a message with subject or body 'help' to
> towertalk-request@contesting.com
>
> You can reach the person managing the list at
> towertalk-owner@contesting.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of TowerTalk digest..."
>
>
> Today's Topics:
>
> 1. Re: Trouble mounting T-2X (Roger (K8RI))
> 2. Re: Trouble mounting T-2X (Dick Green WC1M)
> 3. Re: Trouble mounting T-2X (Robert)
> 4. Rotators control software (Codrut Buda)
> 5. Re: TowerTalk Digest, Vol 87, Issue 65 (K7LXC@aol.com)
> 6. Re: Trouble mounting T-2X (Bob Alexander)
> 7. Re: comparing top section of crankup to (Steve, W3AHL)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 20 Mar 2010 23:38:34 -0400
> From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
> Subject: Re: [TowerTalk] Trouble mounting T-2X
> To: "Tower and HF antenna construction topics."
> <towertalk@contesting.com>
> Cc: w4lde@numail.org
> Message-ID: <4BA594BA.9040702@tm.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
>
> Bill Aycock wrote:
>> The owners manual says the bolts are 5/16-18, 1 5/8 long. The manual
>> shows a
>> diagram with some unthreaded length.
>> Bill-W4BSG
>>
> It's the hole that needs to be threaded all the way through. Normally
> the unthreaded portion of a bolt is smaller than the threaded portion.
>> ----- Original Message -----
>> From: "w4lde" <w4lde@numail.org>
>> To: <wc1m73@gmail.com>; "Tower and HF antenna construction topics."
>> <towertalk@contesting.com>
>> Sent: Saturday, March 20, 2010 3:50 PM
>> Subject: Re: [TowerTalk] Trouble mounting T-2X
>>
>>
>>
>>> Dick,
>>>
>>> Looks like the bolts are 1 1/2" long and either a 1/4" or 3/16" and my
>>> guess is a 3/16" I believe its 20 threads per inch. There is no
>>> markings on the bolt
>
> No lines on the head, like one to each flat or so? Then it's a low
> grade, which is fine in this case.
>>> and a standard 1/2" socket fits a little loose and
>>> not a snug as I expected, so I wonder if its metric? Probably made in
>>> China.
>>>
> Unless they've changed recently the bolts should still be 5/16-18 unless
> some one accidentally slipped in the wrong bolts. More than once I've
> picked up bolts at the big box stores and found a few "odd" ones in
> there. IE...sorted by customer.
>
> 73
>
> Roger (K8RI)
>>> 73 de
>>> Ron W4LDE
>>>
>>
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>
>
> ------------------------------
>
> Message: 2
> Date: Sun, 21 Mar 2010 00:12:00 -0400
> From: "Dick Green WC1M" <wc1m73@gmail.com>
> Subject: Re: [TowerTalk] Trouble mounting T-2X
> To: <w4lde@numail.org>, <wc1m73@gmail.com>, "Tower and HF antenna
> construction topics." <towertalk@contesting.com>
> Message-ID: <003801cac8ac$a8bd0350$fa3709f0$@com>
> Content-Type: text/plain; charset="us-ascii"
>
> Ron,
>
> My T2X mounting bolts measure out to what W4BSG says is in the manual:
> 1-5/8" long (+/-), 5/16" diameter, 18 threads per inch. A 1/2" socket is
> slightly loose, but that's the correct size.
>
> I think the mounting holes in the rotor go through the base plate into the
> body of the rotor. I was able to stick a 3 1/4" screwdriver into the holes
> without bottoming out.
>
> The bolts fit tight, and I was not able to screw them in by hand more than
> 1/4"-1/2". But I was able to screw them all the way in with a ratcheting
> wrench, without using excessive force. The bolts are stainless, so you
> have
> to be very careful to make sure they're aligned properly or they'll seize.
> I
> always use a thin coat of Never-Seize or equivalent on stainless bolts to
> prevent seizing. That'll make it easier to thread the bolts in, too.
>
> Note that my T2X is an older model manufactured by Hy-Gain and refurbished
> by Norm's. If your T2X is a new one manufactured after the acquisition by
> MFJ, it's conceivable that MFJ has changed the spec on the bolts. But I
> doubt it.
>
> Once you confirm the spec and get the right bolts, if they still don't fit
> well try running a 5/16-18 tap through the holes and run the bolts through
> a
> 5/16-18 die. Again, if the bolts are stainless, use anti-seizing compound
> when screwing the bolts into the rotor base.
>
> NOTE: In some installations, the mounting bolts have a habit of working
> loose. Some people use thread locking compound to prevent this. I've never
> had to do that with a T2X mounted on a standard rotor plate, but I did
> have
> to do it with a mast-mounted T2X. The bolts fixing the lower mast clamps
> to
> the rotor tended to work loose unless I used thread locking compound.
> Before
> it setup, the thread locking compound did a reasonable job preventing the
> stainless bolts from seizing as I screwed them in.
>
> 73, Dick WC1M
>
>> -----Original Message-----
>> From: w4lde [mailto:w4lde@numail.org]
>> Sent: Saturday, March 20, 2010 4:50 PM
>> To: wc1m73@gmail.com; Tower and HF antenna construction topics.
>> Subject: Re: [TowerTalk] Trouble mounting T-2X
>>
>> Dick,
>>
>> Looks like the bolts are 1 1/2" long and either a 1/4" or 3/16" and my
>> guess is a 3/16" I believe its 20 threads per inch. There is no
>> markings on the bolt and a standard 1/2" socket fits a little loose and
>> not a snug as I expected, so I wonder if its metric? Probably made in
>> China.
>>
>> 73 de
>> Ron W4LDE
>>
>> On 3/20/2010 12:39 PM, Dick Green WC1M wrote:
>> > What are the dimensions of the bolts -- length, diameter and threads
>> > per
>> > inch? Also what is the depth of the holes? I can measure the bolts and
>> holes
>> > on a T2X I have on the ground and let you know how they compare.
>> >
>> > 73, Dick WC1M
>> >
>> >
>> >> -----Original Message-----
>> >> From: w4lde [mailto:w4lde@numail.org]
>> >> Sent: Saturday, March 20, 2010 11:02 AM
>> >> To: TowerTalk
>> >> Subject: [TowerTalk] Trouble mounting T-2X
>> >>
>> >> Started to mount a new T-2X purchased on 3/3/10 yesterday. Made up
>> >> all
>> >> of the plugs and checked the rotor out on the ground at the tower.
>> >> Rotor worked properly on the ground
>> >>
>> >> Dropped the tower and tilted it over so we could install the rotor
>> >> body
>> >> and mast. We checked the bolts and the tower mounting plate for the
>> >> correct mounting and they aligned OK. The rotor plate is heavy duty
> 3/8
>> >> to 1/2" thick and welded in place.
>> >>
>> >> I had only insert the mounting bolts in the body a few turns before
>> >> taking it outside and didn't notice anything unusual. Used some anti
>> >> seize lube' on the bolts.
>> >>
>> >> My helper (brother) did notice that the rotor body bolt holes seemed a
>> >> little out of the pattern and very close to one edge, however, when
>> >> aligning the body to the rotor plate they look almost dead on. So we
>> >> proceeded, then the trouble started.
>> >>
>> >> The mounting bolts turned in hand tight about a 1/4 of the way in, not
>> >> free at all and got to the point (1/4 way) that we decided to use my
>> >> small ratchet set.
>> >>
>> >> Not even 1/2 way in the bolts started to seize and we were very
>> >> reluctant to proceed. I checked the depth of the holes in the body
>> >> and
>> >> they are free in equal to the length of the bolts.
>> >>
>> >> We backed out the bolts and lowered the rotor to the ground and again
>> >> tired to insert and screw in the bolts while free of any mounting
>> >> plate
>> >> with the same results. It almost seems like the threads are not right
>> >> for the mounting bolts or the bolts are two long but we didn't want to
>> >> over tighten. The bolts were in a plastic package so I assume they
>> >> were
>> >> the correct ones supplied by the factory.
>> >>
>> >> Looks like we did slightly bend one bolt head and not sure when that
>> >> occurred but I can always get a new bolt locally.
>> >>
>> >> Any ideas? Your input and help will be appreciated.
>> >>
>> >> 73 de
>> >> Ron W4LDE
>> >>
>> >
>> > _______________________________________________
>> >
>> >
>> >
>> > _______________________________________________
>> > TowerTalk mailing list
>> > TowerTalk@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/towertalk
>> >
>> >
>
>
>
> ------------------------------
>
> Message: 3
> Date: Sat, 20 Mar 2010 19:52:26 -0700
> From: "Robert" <rgshauger@myyellowstone.net>
> Subject: Re: [TowerTalk] Trouble mounting T-2X
> To: <w4lde@numail.org>, "Tower and HF antenna construction topics."
> <towertalk@contesting.com>
> Message-ID: <A97AA8F378D340F3B4F6A98A3197896E@companyikphi8v>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> T2X = 5/16-18
> H4 = 1/4-20
>
> ----- Original Message -----
> From: "w4lde" <w4lde@numail.org>
> To: <wc1m73@gmail.com>; "Tower and HF antenna construction topics."
> <towertalk@contesting.com>
> Sent: Saturday, March 20, 2010 1:50 PM
> Subject: Re: [TowerTalk] Trouble mounting T-2X
>
>
>> Dick,
>>
>> Looks like the bolts are 1 1/2" long and either a 1/4" or 3/16" and my
>> guess is a 3/16" I believe its 20 threads per inch. There is no
>> markings on the bolt and a standard 1/2" socket fits a little loose and
>> not a snug as I expected, so I wonder if its metric? Probably made in
>> China.
>>
>> 73 de
>> Ron W4LDE
>>
>> On 3/20/2010 12:39 PM, Dick Green WC1M wrote:
>>> What are the dimensions of the bolts -- length, diameter and threads per
>>> inch? Also what is the depth of the holes? I can measure the bolts and
>>> holes
>>> on a T2X I have on the ground and let you know how they compare.
>>>
>>> 73, Dick WC1M
>>>
>>>
>>>> -----Original Message-----
>>>> From: w4lde [mailto:w4lde@numail.org]
>>>> Sent: Saturday, March 20, 2010 11:02 AM
>>>> To: TowerTalk
>>>> Subject: [TowerTalk] Trouble mounting T-2X
>>>>
>>>> Started to mount a new T-2X purchased on 3/3/10 yesterday. Made up all
>>>> of the plugs and checked the rotor out on the ground at the tower.
>>>> Rotor worked properly on the ground
>>>>
>>>> Dropped the tower and tilted it over so we could install the rotor body
>>>> and mast. We checked the bolts and the tower mounting plate for the
>>>> correct mounting and they aligned OK. The rotor plate is heavy duty
>>>> 3/8
>>>> to 1/2" thick and welded in place.
>>>>
>>>> I had only insert the mounting bolts in the body a few turns before
>>>> taking it outside and didn't notice anything unusual. Used some anti
>>>> seize lube' on the bolts.
>>>>
>>>> My helper (brother) did notice that the rotor body bolt holes seemed a
>>>> little out of the pattern and very close to one edge, however, when
>>>> aligning the body to the rotor plate they look almost dead on. So we
>>>> proceeded, then the trouble started.
>>>>
>>>> The mounting bolts turned in hand tight about a 1/4 of the way in, not
>>>> free at all and got to the point (1/4 way) that we decided to use my
>>>> small ratchet set.
>>>>
>>>> Not even 1/2 way in the bolts started to seize and we were very
>>>> reluctant to proceed. I checked the depth of the holes in the body and
>>>> they are free in equal to the length of the bolts.
>>>>
>>>> We backed out the bolts and lowered the rotor to the ground and again
>>>> tired to insert and screw in the bolts while free of any mounting plate
>>>> with the same results. It almost seems like the threads are not right
>>>> for the mounting bolts or the bolts are two long but we didn't want to
>>>> over tighten. The bolts were in a plastic package so I assume they were
>>>> the correct ones supplied by the factory.
>>>>
>>>> Looks like we did slightly bend one bolt head and not sure when that
>>>> occurred but I can always get a new bolt locally.
>>>>
>>>> Any ideas? Your input and help will be appreciated.
>>>>
>>>> 73 de
>>>> Ron W4LDE
>>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
> ------------------------------
>
> Message: 4
> Date: Sat, 20 Mar 2010 22:24:48 +0200
> From: Codrut Buda <codrut.buda@gmail.com>
> Subject: [TowerTalk] Rotators control software
> To: towertalk@contesting.com
> Message-ID:
> <50c06761003201324r66fcd76enefb62012b83c12e1@mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> PstRotator - http://www.qsl.net/yo3dmu/index_Page346.htm - a program for
> rotators control - was just updated. Some new rotator controllers are
> available (Winrotor FUNKBOX, ERC-3D, EGIS, RC2800P-A, RC1-MDS), and some
> new
> loggers (Ham Radio Deluxe, Logger32, Winlog32, LOG-X, Loki5ace) are
> supported.
> 73,
> Codrut - YO3DMU
>
>
> ------------------------------
>
> Message: 5
> Date: Sun, 21 Mar 2010 07:20:26 EDT
> From: K7LXC@aol.com
> Subject: Re: [TowerTalk] TowerTalk Digest, Vol 87, Issue 65
> To: towertalk@contesting.com, w3nj@aol.com
> Message-ID: <6ca78.14f1169f.38d75afa@aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
>
> In a message dated 3/20/2010 5:33:06 P.M. Pacific Daylight Time,
> towertalk-request@contesting.com writes:
>
>> Where this best place to get a primer and details on:
>
>> Sizing the tower to handle the load (I have the info from Steppir's
>> page
> All the "prep work" for the base forms, concrete type, "tips/tricks"
> All the "legal (permits, etc) stuff to raise the tower. (I'm in a
> subdivision and the good news is that there are a couple hams nearby with
> towers so
> I hope I can use "precedence" to allow another tower to go up.My lot is
> approx 60 x 120, so not a lot of space to work with
> All utilities are underground (made that a requirement when we moved to
> Austin in 1985)
> Pros/cons ($$s) of motorized raising option for the tower.
>
>
> First, congratulations on your proposed new installation.
> You'll have fun with it!
>
> May I suggest getting a copy of my book UP THE TOWER - The
> Complete Guide To Tower Construction (available from
> _www.championradio.com_
> (http://www.championradio.com) )? It'll answer almost all of your
> questions.
> YOU and others in your situation are the reason why I wrote it. BTW it's
> the first and only tower construction book available.
>
> IMO crank-ups are worth their extra cost and decreased
> reliability in some situations but nothing beats a real fixed tower for
> value and
> long term use - whether it's a guyed or self-supporting structure.
>
> And you've done the right thing by asking your questions on
> TowerTalk. You'll get lots of useful advice from the members.
>
> Cheers & GL,
> Steve K7LXC
> Champion Radio Products
> Cell: 206-890-4188
>
>
> ------------------------------
>
> Message: 6
> Date: Sun, 21 Mar 2010 08:21:59 -0500
> From: Bob Alexander <realex@flash.net>
> Subject: Re: [TowerTalk] Trouble mounting T-2X
> To: "Tower and HF antenna construction topics."
> <towertalk@contesting.com>
> Cc: w4lde@numail.org
> Message-ID: <4BA61D77.7050209@flash.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Roger (K8RI) wrote:
>> Bill Aycock wrote:
>>
>>> The owners manual says the bolts are 5/16-18, 1 5/8 long. The manual
>>> shows a
>>> diagram with some unthreaded length.
>>> Bill-W4BSG
>>>
>>>
>> It's the hole that needs to be threaded all the way through. Normally
>> the unthreaded portion of a bolt is smaller than the threaded portion.
>>
> Gentlemen,
> Sounds to me like something has been changed in the manufacturing
> process for the T2x.
> I bought one about 6 years ago and have had the exact opposite
> problem... the bolts will not
> stay tight.
>
> A few months after I installed the rotor I got home from work one day
> and my XYL handed me
> a bolt and said she found it in the yard. I knew exactly where it came
> from and went up the tower
> to check it out. Only two bolts were still in the rotor. All had been
> installed properly with lock washers.
> The two still in the rotor were loose. After a thorough search I found
> the missing bolts and reinstalled
> everything.
> Over the next couple of years I had to re-tighten the bolts once or
> twice a year. I finally used liberal
> amounts of RED Locktite on them and have not had any problems since
> then... at least not with mounting bolts.
>
> 73, Bob, W5AH
>
>
> ------------------------------
>
> Message: 7
> Date: Sun, 21 Mar 2010 09:30:00 -0400
> From: "Steve, W3AHL" <w3ahl@att.net>
> Subject: Re: [TowerTalk] comparing top section of crankup to
> To: <towertalk@contesting.com>
> Message-ID: <E6CF8FDAE9274B6BB026FC3197F3B7DC@W3AHLLAP2>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Kevin,
>
> Without seeing the full report, I can't answer your specific issues, but
> I would accept the analysis as valid for the standards used at the time.
>
> It appears that the tower's wind load is limited by the moment at the
> base, if the base F.S.=0.98 and top F.S. is <0.5. Therefore using the
> Equivalent Moment method of determining what the allowable antenna
> projected area is on a mast extending above the top of the tower stub is
> appropriate. This is consistent with Travanty's article and the ARRL
> Antenna book methods in chapter 22.
>
> Regarding analyzing allowable mast loads using a spreadsheet, you
> misinterpret what my point was. There is nothing wrong with electrical
> resistance welding of seams in pipe or tubing, if the process & material
> complies with the specification required for the application. The only
> testing done on A53 Type E Grade B 2" pipe is typically a hydrostatic
> pressure test, which is not adequate for structural use. There is no test
> to determine if the weld seam yield strength is the same as the rest of
> the pipe. Larger sizes of A53 require NDT and ductility testing to verify
> the weld seam is as strong as the base pipe material. Therefore standard
> stress analysis formulas are valid for predicting how the material will
> respond to structural loading.
>
> I haven't found a good reference book that would serve as a tutorial on
> tower design and stress analysis for those without mechanical engineering
> degrees. There are many good engineering and materials texts at
> university libraries, but none that detail the specific issues with
> antenna supports. The TIA RS-222-C, -F and -G standards are worth
> reading. The current -G version is less straightforward than earlier
> versions and costs $600. Check your nearest university engineering
> library for a copy.
>
> Steve, W3AHL
>
> Date: Sat, 20 Mar 2010 19:02:58 -0700
> From: Kevin Normoyle <knormoyle@surfnetusa.com>
> Subject: Re: [TowerTalk] comparing top section of crankup to unsupported
> To: "Tower and HF antenna construction topics."
> <towertalk@contesting.com>
>
> ..snip...
> For the top section this results in F'a/fa = 2.49
> My reading is that means a 2.49 safety factor, for that assumed antenna
> load.
> The same safety factor appears to be only 0.98 (which they take to be
> one. ...i.e. they see fa of 33,350 psi in the bottommost base legs (and
> F'a allowed of 32,530 psi)
>
> ..snip..
>
> On the mast thing: it sounds like the spreadsheet stuff is worthless,
> because we can't just analyze using yield strength. The manufacturing
> process is important (although I've never seen a photo of a split weld).
> The mast spreadsheets then are only good for some set of manufacturing
> processes. (and it's not just about electric resistance welding or
> not...I thought a lot of DOM starts out as ERW?)
>
> ..snip..
>
> -kevin
> AD6Z
>
>
> ------------------------------
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> End of TowerTalk Digest, Vol 87, Issue 67
> *****************************************
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|