Pointy tops on Rohn 25

K7LXC at aol.com K7LXC at aol.com
Thu Apr 11 21:08:19 EDT 1996

In a message dated 96-04-11 19:34:38 EDT, you write:

>I have a pointy top on my tower (Rohn 25)
>Is there any type of thrust bearing I can use with this type top to releive
>some of the wieght from the rotor?  Due to some metal stress my quad is down
>right now and while waiting for the repair part it would seem to be a good
>time to add  a bearing if it is possible.

Hiya, George --

     You need a flat plate to mount a TB-3 (2 inch) Rohn thrust bearing.
 Since the tapered top section that you described (and there are several
different versions of them) is really designed for communications users and
not necessarily amateurs, the only way to use a thrust bearing is to get
another accessory shelf in the tower and mount the thrust bearing on it with
the mast going up through the top pipe.  Unless you've got a big load (mast
plus antenna - weight and square footage), I wouldn't worry about the thrust
bearing and just let the rotator take the vertical weight.    Most rotators
will take a bunch of vertical weight so it's not a big deal.  Yes, it's
probably better to have the antenna and mast weight taken by a thrust bearing
but the investment in your case may not justify it.  Although you didn't
mention how big your quad was, I imagine it was a 2 or 3 element HF quad.  If
so, the above comments apply.

      Let me know if I misrepresented your installation or if you want
additional info.

73,   Steve    K7LXC   

>From Gary Schwartz <garyk9gs at solaria.sol.net>  Fri Apr 12 01:46:05 1996
From: Gary Schwartz <garyk9gs at solaria.sol.net> (Gary Schwartz)
Date: Thu, 11 Apr 1996 19:46:05 -0500 (CDT)
Subject: Pointy tops on Rohn 25
Message-ID: <Pine.3.02.9604111903.A28869-b100000 at solaria.sol.net>

On Thu, 11 Apr 1996, AA3JU George Cook wrote:

> I have a pointy top on my tower (Rohn 25)
> Is there any type of thrust bearing I can use with this type top to releive
> some of the wieght from the rotor?  Due to some metal stress my quad is down
> right now and while waiting for the repair part it would seem to be a good
> time to add  a bearing if it is possible.
> George
> AA3JU  george at epix.net    AA3JU at W3PYF

I would suggest putting the thrust bearing on a modified rotor shelf
beneath the tapered portion of the top section.  You have to be very
careful to align things well because of the "sleeve" on the section.  This
is not a place where you want them to bind.

Gary K9GS 
  /       K9GS       |______________________________
 /   FP/K9GS, TO5M   |Society of Midwest Contesters |____________________
(                    |   garyk9gs at solaria.sol.net   |Secretary/Treasurer/
 \   Gary Schwartz   |   K9GS at WA9KEC.WI.USA.NOAM    | Greater Milwaukee/
  \__________________|     PacketCluster: NB9C      |  DX Association (
                   (________________________________|       GMDXA      \

>From Tom Francis <tomf at neca.com>  Fri Apr 12 02:00:12 1996
From: Tom Francis <tomf at neca.com> (Tom Francis)
Date: Thu, 11 Apr 1996 21:00:12 -0400
Subject: pow-wow on internet
Message-ID: <199604120100.VAA26614 at orion.neca.com>

At 02:23 PM 4/11/96 -0500, you wrote:
>hi all
>a non-ham friend just told me about a new internet chat line called pow-wow.
>real time conversations with a MICROPHONE anywhere in the world.
>has anyone else heard of this?
>de AC5CT...mike in tx

        It's not a chat line in that sense - it opens a channel
        between you and anyone else that has the powwow software - 
        works off your Email address - it's pretty cool....

        Go to Yahoo or Altavista and get the URL for Tribal Voice
        and pick up the latest version - it supports 14.4 sound
        so you can use a microphone - at 28.8 it's like a radio,
        hi hi..

        I've been using it for about a year and it's pretty neat.

        Powow also is multi featured - transfer files, pictures,
        all kinds of neato stuff...

        Good luck - hope this helps you out..


        Tom, NM1Q (tomf at neca.com)

        "Clunk enough people on the head and
         we'll have a nation of lump heads!"
                                Foghorn Leghorn



>From David & Barbara Leeson <0005543629 at mcimail.com>  Fri Apr 12 02:31:00 1996
From: David & Barbara Leeson <0005543629 at mcimail.com> (David & Barbara Leeson)
Date: Thu, 11 Apr 96 20:31 EST
Subject: Quieting Amplifiers
Message-ID: <30960412013103/0005543629DC4EM at MCIMAIL.COM>

You can make a manometer with 1/4" clear plastic tubing, which plugs right
over a standard RCA connector.  Make a "U" loop and fill with just enough
water (colored with food coloring if desired) so you can measure the
difference in the tops of the water in each side of the U.

But, be careful with water around line voltage and high voltage!  You
don't want to accidently lift the end of the manometer and dump the water
into the amplifier plenum.

Fans and blowers have an odd variation of flow rate with back pressure,
so slowing a blower by lowering the voltage (Alpha trick) must be done
while measuring to be sure you have enough pressure.

Some tubes, such as the 8877, require enough air to be loud no matter
what you do.  I asked a former Eimac employee how he stood the noise
of his 8877 amp, and the answer was "headphones".  Amps with multiple
smaller tubes in parallel are typically quieter (e.g., Alpha 76, 78,
87 etc.).  There is a big difference in the noise made by various fans
and blowers, so it's worth auditioning them.  As an example, there is
a certain Sanyo fan that is prized by Mac SE owners as being much
quieter, and there's a squirrel cage blower for the same box that's
loud enough to require ear protectors.

I once went so far as to put the blower for an 8877 rig below the floor,
then used stove pipe with elephant trunk (dryer tubing) joints.  If I
used only elephant trunk, the pressure loss was too great.  It didn't
really make much of a difference.  I also tried using a light dimmer to
get the blower to just the right speed, but I always worried about it
being unreliable.  Now the amp is in the closet as a backup.

BTW, there was a batch of bad 8877's a number of years ago, and I wonder
if the cheap ones you see advertised come from that batch.  They had the
problem of very short life, due to gold migration from the grid to the
cathode if I remember right.  Buyer beware.  Eventually, they fixed
the problem, so current tubes aren't a problem.

For lessons on how best to quiet amplifiers, see any Alpha.  But I've
always been worried about the fact that you could contact the HV on the
tube if you (or a child) dropped a small wire, drill, screwdriver or
pencil through the vent holes.  I told that any baffling upsets the
airflow and increases the noise, but I haven't any first-hand experience.

GL, 73 de Dave, W6QHS

>From Steve Lufcy <km0l at tyrell.net>  Fri Apr 12 03:05:49 1996
From: Steve Lufcy <km0l at tyrell.net> (Steve Lufcy)
Date: Thu, 11 Apr 1996 21:05:49 -0500 (CDT)
Subject: Contest Free Zones
Message-ID: <Pine.SUN.3.91.960411203750.1503A-100000 at tyrell.net>

To the best of my knowlege and experience there have always been 
gentlemans agreement type zones on all bands where very little, if any 
contest activity occurs- towards the top end of the bands:
160- 1.9 mhz +
 80- 3.9 +
 40- 7.26 +
 20- 14.325+
 15- 21.400+
 10- 28.7 +
I used to hold scheds with my father and brother (both sk's now) on 
14.330 even on contest weekends, with no problems.
My complaint is the folks who fire up on 3.835 at 9:00 PM local, and 
complain about those damn contesters - we sure are  rotten lot to 
interfere with their "QSO" on their frequency.
I think we contesters go a very long way to accomodaate other users of 
the spectrum and to coexist. The illegal, intentional interference of a 
few "pig farmers" is the problem here.
The contest community haas already made contest free zones if the 
complainers would look and listen.
My opinion based on the contests I operate (all according to my wife) and 
Please notice there are no cw freq's shown above. I do not believe anyone 
who works the cw bandsbands will think this problem exists on cw.
Thaanks for letting me spout with a minimum of QRM.
73 de KM0L

On 10 Apr 1996, Hans Brakob wrote:

> Most of the commentary posted here on this subject has tended to
> "Its our right....  they can just go to CW (or phone, or WARC, or 
> whatever the contesters arent doing this weekend.)"
> Technically, under FCC jurisdiction, that hardnosed position is
> defensible under the "no one has a reserved frequency" concept in
> the rules.
> In real life, however, it is analogous to the organizers of the 
> Boston Marathon saying "We are running our race once a month on most
> of the main streets, and the rest of you folks will just have to 
> take some back streets, or change your mode of travel on those 
> weekends." How long would it be before the citizens of Boston would
> convince the city council to outlaw marathons?
> On the other hand, what if the Marathon organizers agreed only to
> use certain traffic lanes on each street in their route, and leave 
> the remaining lanes free for normal traffic?  Yes, there would be
> some small percentage (marathon haters and pig farmers) whod 
> complain about "those damn runners", but most folks would probably 
> accept some slightly crowded traffic for the weekend, and maybe even 
> make a point to come out and watch. Some of those "watchers" might 
> even get caught up in the excitement and join up for the next race.
> Personally, as a contester, I think it is time that we seriously
> consider some voluntary plan which will make us less obnoxious to
> other users of the band on contest weekends, regardless of our
> "rights" to be so.  Yes, there will be some non-contesters who will
> complain that "their" net/ragchew frequency was disrupted no matter
> what we do, but at least we will be able to point to some "safe 
> haven" on each band where they can chat with Uncle Jim in East 
> Overshoe. That will go a long way towards blunting any regulatory 
> petition, and might even convince a few folks that "those 
> contesters arent so bad after all, maybe Ill give it a try." 
> (And, yes, you can bet there WILL be a persuasive petition some day.
> Not everyone else out there is a pig farmer.)
> 73, de Hans, K0HB
> PS: I really do want to discuss this, but any response blindly
> "waving their rights" will be ignored.

>From Fred Hopengarten" <k1vr at k1vr.jjm.com  Thu Apr 11 01:19:03 1996
From: Fred Hopengarten" <k1vr at k1vr.jjm.com (Fred Hopengarten)
Date: Wed, 10 Apr 1996 20:19:03 EDT
Subject: Stacking TH7's
Message-ID: <316c500c.k1vr at k1vr.jjm.com>

On Tue, 9 Apr 1996 17:56:38 -0400 (EDT), "Bruce (AA8U)" <aa8u at voyager.net>
> TH7's are currently on separate 55G towers, but I am considering putting
> them both on the 40M quad tower at 45' and 85' fixed on 45 deg.

> Have any of you tried stacking TH7's and if so have you found it worth the
> effort? How about the ring-rotor aspect?

K1VR:  See article in QST February 1995 by N6BV and K1VR on stacking TH7's.
I love 'em.  In fact, I now have a TH6 at 97' over a TH6 at 61' over a TH7
at 31'.

> The 40' spacing probably would favor 15M, being a bit close on 20M
> for any significant stacking gain. The variety of elevation angles might
> make it a worthy project anyway.

K1VR:  Yes it will be worthy.  W2PV's stacking curves show that stacking gain
is a very gentle curve.  Thus, exact stacking distance is not critical.

> Somewhere I recall seeing a very tall tower with three of four TH7's. Maybe
> it was AA6TT.

K1VR:  I think it was N5RM.
                      Fred Hopengarten K1VR
           Six Willarch Road * Lincoln, MA 01773-5105
     home + office telephone:  617/259-0088 (FAX on demand)
                   internet:  k1vr at k1vr.jjm.com
            "Big antennas, high in the sky, are better
                       than small ones, low."

>From Hans Brakob <71111.260 at CompuServe.COM>  Fri Apr 12 04:39:34 1996
From: Hans Brakob <71111.260 at CompuServe.COM> (Hans Brakob)
Date: 11 Apr 96 23:39:34 EDT
Subject: Contest Free Zones
Message-ID: <960412033933_71111.260_EHM60-1 at CompuServe.COM>

Steve, KM0L points out:

>To the best of my knowlege and experience there have always been 
>gentlemans agreement type zones on all bands where very little, 
>if any contest activity occurs - towards the top end of the 

Thanks Steve, you make a valid point. (And congrats on your
stations top-ten showing in the SS CW listings.)

Whether or not there has ever actually been a conscious "agreement", 
Steve is correct in saying that the high ends of the bands tend to 
be "contest free". Since this is true, it may represent an 
opportunity for us in the contesting community to polish our image,
with little, if any, impact on our operations during contests.

If these defacto CFZ's exist, then perhaps we should publicly 
declare in our contest rules that they exist. We already have
precedent for a similar situation in our protection of the DX
window on 160, and we seem to successfully use peer pressure to
enforce it. Such a declaration, at little cost to us, would go
a long way toward defusing the complaints about "those arrogant
contesters clobbering the whole spectrum ever weekend".

A pragmatic rascal once said "If it appears you are in danger of
being run out of town, get out ahead of the thing and make it look 
like you are leading a parade."  Why not give a parade.... it will
confound our vocal detractors and make us look like good citizens 
to everyone else.

73, de Hans, K0HB

>From Bill Turner <wrt at eskimo.com>  Fri Apr 12 05:14:47 1996
From: Bill Turner <wrt at eskimo.com> (Bill Turner)
Date: Thu, 11 Apr 1996 21:14:47 -0700
Subject: Contest Exchange
Message-ID: <199604120415.VAA07775 at mail.eskimo.com>

At 09:27 AM 4/8/96 -0400, Tony Brock-Fisher wrote:
>>How 'bout just requiring "real" signal reports.  In other words, any station
>>transmitting nothing but 59s or 599s would be DQ'd.  The receiving station's
>>log would have to match whatever was sent.  We'd all get and give some
>>useful information that way, especially over the course of a contest.
>No Good. How many non-59's does it take? 1? 100? Whatever it is,
>the contesting masses would just do their share of 58's until they
>'made the quota'.
>-Tony, K1KP, fisher at hp-and2.an.hp.com
I didn't mean sending all 59s or 58s... I meant they should be all clearly
random (just like real operating) and all had to MATCH the report at the
receiving end.  That way, neither sending or receiving station could fudge.
I grant you, some guys would try to push it and do a bunch of 59s followed
by a few true reports and then back to 59s, but after a while I suspect it
would become a pain to try to keep it straight and they would just start
giving out the real thing... maybe.  Could be I'm just wishful thinking, but
I really would like to receive a whole bunch of TRUTHFUL reports during a
contest.  I can't think of any better way to evaluate my station's
performance.  Any one signal report doesn't mean much, but a couple hundred
in a short time could be really useful.  

Certainly more useful than some hex-encoded random number.

73, Bill  W7LZP
wrt at eskimo.com

>From AA1K Jon Zaimes <jon.zaimes at dol.net>  Fri Apr 12 08:12:24 1996
From: AA1K Jon Zaimes <jon.zaimes at dol.net> (AA1K Jon Zaimes)
Date: Fri, 12 Apr 1996 04:12:24 -0300
Subject: Pointy tops on Rohn 25

Hi George...you could mount a spare rotor plate (AS25G is the number i
think) above the rotor and mount a TB3 or other bearing on the rotor plate.
Jack the mast up slightly so it isn't sitting fully on the rotor base (just
stick a screwdriver or somthing between the bottom of the bast and the
rotor; just lift it a quarter inch or so above the normal nesting spot in
the rotor) and then tighten down on the TB3 bolts. Then tighten the mast
clamps on the rotor.

This arrangement will also allow you to remove the rotor for repair easily.

73/Jon AA1K  jon.zaimes at dol.net

At 19:12 4/11/96 -0400, AA3JU George Cook wrote:
>I have a pointy top on my tower (Rohn 25)
>Is there any type of thrust bearing I can use with this type top to releive
>some of the wieght from the rotor?  Due to some metal stress my quad is down
>right now and while waiting for the repair part it would seem to be a good
>time to add  a bearing if it is possible.
>AA3JU  george at epix.net    AA3JU at W3PYF
>Proudly  F R C...........
>"FRC When second best just isn't good enough!"

>From steve.hajducek at bytewise.org (Steve Hajducek)  Fri Apr 12 03:58:00 1996
From: steve.hajducek at bytewise.org (Steve Hajducek) (Steve Hajducek)
Date: Thu, 11 Apr 96 18:38:00 -0820
Subject: :New Software for Amateur Radio Callbook
Message-ID: <127.2738.17 at bytewise.org>

Since being informed that many users of this forum have discussed the
subject of the new Amateur Radio callbook CD-ROM, and its acompaning
software, I felt that this message would be of interest and help.

Subject: RAC 'n Rollup Callbook Software Demo Released.
>From   : Steve Hajducek, N2CKH

The Demonstration/Sharware version of RAC 'n Rollup is now available
for all interested parties.

RAC 'n Rollup is an MS-Windows based program which acts as a front
end for the excellent Radio Amateur Callbook, Inc. CD-ROM database
released in November 1995.

Users enter a U.S. or Foreign callsign (no need to select database)
and when found, all pertainent information is displayed. The user can
queue data for mailing label printing or copying to the clipboard.

Provided are full country resolution with a custom prefix search
engine that works with callsign lookup or alone. Also provided is
the Continent, CQ Zone and for U.S. stations Grid Square. No grids
are provided for foreign callsigns at present.

Full mailing label printing is supported as is copy to the Windows
clipboard. Additional needed features such as mailing label Callsign
printing ON/OFF and others are provided.

RAC 'n Rollup is a subclassing rollup type application, which means
that when it is not in use, it takes up only its caption bar height
and width, but is immediately ready to use. The program featues an
uncluttered user interface with graphical icons and makes use of a
modified system menu for its program menu.

The purpose of the DEMO version of RAC 'n Rollup is to allow as many
people as possible to opportunity to experience the software without
any obligation to purchase. The demo does NOT print or copy to the
clipboard. It does however allow full access to all databases for
up to six (6) queries at a time.

The DEMO version has NO registration fees and NO support is offered.

It is available on the support BBS at 1-908-363-2760.

It has also been uploaded to the ARRL BBS and the KENWOOD BBS.

The file name is RAC_DEMO.ZIP and is 1.3MB is size and takes about 5
minutes at 14.4KB using Zmodem protocal. It will be placed on various
FTP sites as time permits.

Please do not hesitate to e-mail any comments or bug reports, my
desire is to provide the best possible product to the Amateur Radio
community as I can.

RAC 'n Rollup now shipping and is only $ 9.95 U.S. plus $ 1.50 U.S.
shipping/handling in the U.S. or $ 5.00 shipping/handling overseas.

Send your orders with Callsign, e-mail address and mailing address to:

RAC 'n Rollup
C/O Stephen B. Hajducek
U.S. Post Office Box 8
Morgranville, New Jersey

Please makes checks or money orders payable to Stephen B. Hajducek.

Thank you.

/s/ Steve, N2CKH

| ByteWise(tm) BBS - On-line! since 1988 - SYSOP: Steve Hajducek N2CKH |
|  Public access via Node 1 at 1-908-363-2760, 2400-28.8KB 24hrs/day   |
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>From w7ni at teleport.com (Stan Griffiths)  Fri Apr 12 08:22:04 1996
From: w7ni at teleport.com (Stan Griffiths) (Stan Griffiths)
Date: Fri, 12 Apr 1996 00:22:04 -0700 (PDT)
Subject: Pointy tops on Rohn 25
Message-ID: <199604120722.AAA09491 at desiree.teleport.com>

>I have a pointy top on my tower (Rohn 25)
>Is there any type of thrust bearing I can use with this type top to releive
>some of the wieght from the rotor?  Due to some metal stress my quad is down
>right now and while waiting for the repair part it would seem to be a good
>time to add  a bearing if it is possible.
>AA3JU  george at epix.net    AA3JU at W3PYF
>Proudly  F R C...........
>"FRC When second best just isn't good enough!"

Hi George,

I am currently using a 25AG3 top with a thrust bearing.  Here is how I do
it.  I mount the thrust bearing on a AS25G rotator plate specially drilled
for the bearing.  I mount the plate with bearing on it where the rotator
would normally go, about 18 inches below the lower end of the pipe part of
the 25AG3.  I mount the rotator on another plate at the top of the section
just below the bottom of the top section.  I use an 18 foot mast and stack
two beams above the top of the tower about 10 feet apart.  To get the Ham 4
to fit into the tower at the junction of the top and next section down, I
sawed out one of the horizontal members at the bottom of the top section.
It has been working fine this way since 1972.

Stan  w7ni at teleport.com

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