[TowerTalk] TowerTalk Digest, Vol 193, Issue 6

Mon Jan 7 03:23:25 EST 2019

My suggestion is to measure your dummy load out of the circuit. I have had this problem with RF filter networks where the reject load (aka dummy load) is bad & the only indicator is bad VSWR with unusual operation. It typically is not assumed to be a problem. Most of the time the load will eat up power imbalances but when the load is bad, it will reflect the power back into the system causing bad VSWR in that mode. The other modes may not show much VSWR because there just isn’t much imbalance.

Greg Best

Sent from my iPhone

> On Jan 6, 2019, at 11:00 AM, towertalk-request at contesting.com wrote:
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> Today's Topics:
> 
>   1. Kindorf and Unistrut (Jim Thomson)
>   2. Force 12 C-31XR Manual Needed- Round 2 (Tom Hellem)
>   3. US tower remote raising switch (VE6WZ_Steve)
>   4. Re: High SWR on DXE 4sq in OMNI mode (Jorge CX6VM)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sat, 5 Jan 2019 10:51:50 -0800
> From: "Jim Thomson" <jim.thom at telus.net>
> To: <towertalk at contesting.com>
> Subject: [TowerTalk] Kindorf and Unistrut
> Message-ID: <58C9A71B27394065BCE0497AABDDB6F6 at DESKTOPSV54DBH>
> Content-Type: text/plain;    charset="iso-8859-1"
> 
> Date: Fri, 4 Jan 2019 12:26:27 -0600
> From: Jim <jimw7ry at gmail.com>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Kindorf and Unistrut
> 
> <Agreed!
> <And Kindorf and Unistrut also comes in Stainless... Get out your $$ though.
> 
> 
> <Thanks
> <73
> <Jim W7RY
> 
> ##  at the telco I worked at for 34 years,  unistrut was eventually used  all over the offices,
> + cell sites etc.  Also used to support the  24 x 190 kg batteries. They are stacked  12 above 12.
> Several strings are used on the larger offices.  It makes for a fast  install... then the entire mess is hilti 
> anchored to the  concrete  floor, so it all ends up earth quake proof.  
> Also used for a variety  of applications,  including supporting  real heavy  halon bottles.   I even know
> one fellow, who built a spiral  staircase  out of it ! 
> 
> ##  I used unistrut, as a simple way of  re-enforcing the 253 lb dahl xfmr on one of my 
> 19 inch wide x 29 inch deep rack cabs.   One long piece of unistrut, running the entire 
> length, beneath the cab sheet metal, bolted at each extreme end.  And 2  x short pieces, 
> each aprx 8+ inches long, running the width of the 19 inch cab...  dead center, below the xfmr.
> The trick is however, the short pieces can only be bolted at the outboard cab sides. The inboard
> side of each short piece of unistrut cant be bolted,  since the xfmr is right above the mess.  The  fix
> is to use the optional unistrut option of a T shaped plate, that uses the handy dandy spring loaded
> nuts!  That  thick steel  plate bonds the 3 pieces of unistrut, does not budge. On the top side,  I installed 
> a huge sheet of  .25 thick Al plate, to add more strength,and to also make for  grounding points. That same
> optional steel plate can also be used to bond  4 x pieces of unistrut  together.  
> 
> Unistrut makes all sorts of optional pieces for a variety of applications.  The spring loaded nuts  also come
> in several different thread sizes.   We used thousands of feet of it in just one telco office alone.  Its a cheap
> way to get around  problems, without having to resort to custom fabricated steel, welding etc.
> 
> Jim  VE7RF
> 
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Sat, 5 Jan 2019 17:54:50 -0700
> From: Tom Hellem <tom.hellem at gmail.com>
> To: towertalk at contesting.com
> Subject: [TowerTalk] Force 12 C-31XR Manual Needed- Round 2
> Message-ID:
>    <CANyX0ArNO5k4cJCORwc6jFhTppxXYxuu3POV1mGCbTmAHAx5-w at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Hi All-
> I posted a request a few days back for a copy of the manual for a Force 12
> C-31XR yagi.
> Several very generous list members responded and sent me an electronic copy.
> As it turns out I have the separate feedlines version of the antenna and
> the manuals I received are all for the jacketed feed version.
> 
> Does anyone have a manual for the separate feedlines version?
> All I really need is the page showing element placement and tubing lengths,
> and the one or two pages with the information about the hairpin coils for
> the 20 and 15 meter elements. If all you have is a printed manual, a
> scanned copy of these few pages would satisfy my needs.
> 
> Thanks again to all for the help.
> 
> 73
> Tom
> K0SN
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Sat, 5 Jan 2019 19:04:18 -0700
> From: VE6WZ_Steve <ve6wz at shaw.ca>
> To: towertalk at contesting.com
> Subject: [TowerTalk] US tower remote raising switch
> Message-ID: <19675CFE-9E17-4EBD-996B-5F31CD5CD769 at shaw.ca>
> Content-Type: text/plain;    charset=utf-8
> 
> I have been archiving my station notes together into an electronic file so I can easily retrieve them when needed.
> While uploading the files today I recalled a question here on tower talk about adding a remote UP-Down switch functionality to a US Tower, so I thought I would share this.
> 
> Here is a link to my documentation for a relay board I built which emulates the 3PDT UP/DOWN switch which is used on the US tower HDX-589mpl Tower.
> (A lot more ?cost effective? than the US tower remote control box)
> 
> https://drive.google.com/file/d/1IuR1zBhKxquJhoyo6u2hkpHEf0PWsoqe/view?usp=sharing <https://drive.google.com/file/d/1IuR1zBhKxquJhoyo6u2hkpHEf0PWsoqe/view?usp=sharing>
> 
> A +12v or -12V signal will drive the tower up or down while no voltage stops the tower.  Two 4PDT (LY4-DC-12) relays are mounted on an etched board and mounted inside the existing tower switch box.  Terminal blocks mounted on the board allow for a direct install using the same terminal lugs which attach to the existing switch screw terminals.  A schematic of the US tower switch box is included to identify the lug numbers, and a few photos of the installation.
> 
> This relay board has been in service for three years at the VE6WZ remote station and is configured to be remotely controlled either manually as required, or via a windspeed alarm which will automatically drive the tower down above a set windspeed.
> 
> 73, de steve ve6wz.
> 
> ------------------------------
> 
> Message: 4
> Date: Sun, 6 Jan 2019 13:34:49 -0300
> From: Jorge CX6VM <cx6vm.jorge at gmail.com>
> To: Jeff Blaine <KeepWalking188 at ac0c.com>
> Cc: towertalk at contesting.com
> Subject: Re: [TowerTalk] High SWR on DXE 4sq in OMNI mode
> Message-ID: <F61AAC45-4E46-4488-A00A-94B644CDAF4A at gmail.com>
> Content-Type: text/plain;    charset=utf-8
> 
> Hi Jeff
> 
> I had the same issue.
> 
> Individual antennas have 1.1:1 to 1.3:1 but when in OMNI rise up to 2:1
> 
> So Never used OMNI
> 
> 73,
> Jorge
> CX6VM/CW5W
> 
> Enviado desde mi iPad
> 
> El 5 ene. 2019, a la(s) 00:59, Jeff Blaine <KeepWalking188 at ac0c.com> escribi?:
> 
>> My 40m 4sq works just fine in the 4 normal directions.  But when I put it into the OMNI mode, the swr jumps up to about 1.7:1. wondered if anyone had seen this sort of issue and knew what the usual suspect is?
>> 
>> Over frequency both Xj and R move a lot compared with the normal 4 directions.  Makes me wonder if I have not blasted something or broke something.
>> 
>> 73/jeff/ac0c
>> alpha-charlie-zero-charlie
>> www.ac0c.com
>> 
>> _______________________________________________
>> 
>> 
>> 
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> ------------------------------
> 
> End of TowerTalk Digest, Vol 193, Issue 6
> *****************************************