[TowerTalk] Need Comtek manual

Thu Jan 26 17:37:58 EST 2023

 DX Engineering, where I bought the Comteck 8 position switches asked me to send photos and did provide me with the information I needed. They said I bought the switches in 2008, had no idea it was that long ago. If I am satisfied with ham equipment I often buy a backup, which in this instance I never used.
Thanks for the help!
Dave, AL7HG

    On Thursday, January 26, 2023 at 05:26:57 PM EST, towertalk-request at contesting.com <towertalk-request at contesting.com> wrote:  

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Today's Topics:

  1. Re: RG-6 Coax For Receive Loop? (Grant Saviers)
  2. Need Comtek manual (Dave Kaiser)
  3. Re: Need Comtek manual (Jim W7RY)
  4. Re: Need Comtek manual (Tim Duffy)
  5. Assembling a Yagi (Art Greenberg)
  6. Common Mode Choke Locations (Art Greenberg)
  7. Re: Common Mode Choke Locations (Jim Brown)
  8. Re: Assembling a Yagi (Doug Christensen)
  9. Re: Assembling a Yagi (Art Greenberg)
  10. Re: Assembling a Yagi (Art Greenberg)

----------------------------------------------------------------------

Message: 1
Date: Thu, 26 Jan 2023 09:10:58 -0800
From: Grant Saviers <grants2 at pacbell.net>
To: "towertalk at contesting.com" <towertalk at contesting.com>
Subject: Re: [TowerTalk] RG-6 Coax For Receive Loop?
Message-ID: <77af8f38-f8bb-68ea-7a95-46fd7616446d at pacbell.net>
Content-Type: text/plain; charset=UTF-8; format=flowed

Some comments-

RG6 is a good choice, I use it for bidirectional Beverages and for feeds 
to all Rx antennas.

For 80 and below VLF avoid the steel core RG6 since the Cu flash is 
designed for VHF/GHz skin depths.  So the solid Cu center wire is 
available and read the fine print on ebay.

The Thomas & Betts and other premium cable crimp connectors are a must 
with the appropriate prep and crimp tools.

For chassis F female connectors the Amphenol ones with 4 screws are 
highly advised.  The mount won't loosen and the pin grip is solid.  Not 
cheap but chasing noise or faults in phased Rx antennas has not been 
fun. Any knockoffs of these I've found are not well made.

Flooded cable is pretty messy to work with, I prefer burying in a conduit.

IIRC, W8JI made some measurements on shield effectiveness.  Quad shield 
is the standard and again known brands might be advisable.

The usual binocular core transformers which are easy and cheap to make 
are one way to kill CM.  RG316 micro TFE coax wound on smaller #31 
ferrite toroids can yield a compact cheap CM choke also.  Crimp BNC 
connectors are available. I use the large #31 clamp ons on the RG6 at 
each Rx antenna feedpoint if I haven't built in a transformer and/or 
RG213 choke.

Also, I am not a fan of using the RG6 as the means to deliver DC power 
if needed to the Rx elements, especially for home QTH antennas.  Any 
even very high R leakage paths for -xxDbm signals will cause noise, 
likely intermittent, (ask me a how I know) which is super hard to find.

Grant KZ1W

On 1/25/2023 20:10, Tony wrote:
> All:
> 
> I need coax for an amplified receive loop and I'm considering RG-6 as a 
> cheap alternative to the more expensive coax. I'm concerned with 
> common-mode noise and was wondering if quad-shield RG-6 would be better 
> than standard? Also wondering what type of choke to use i.e., material 
> turns etc. The loop is designed for VLF to HF but primary use will be 
> for 160 and 80.
> 
> Thanks, Tony
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk

------------------------------

Message: 2
Date: Thu, 26 Jan 2023 17:26:39 +0000 (UTC)
From: Dave Kaiser <kaiserdr at yahoo.com>
To: "towertalk at contesting.com" <towertalk at contesting.com>
Subject: [TowerTalk] Need Comtek manual
Message-ID: <1398371283.1442019.1674753999624 at mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8

 I am looking for a manual for the Comtek RSV 8 antenna connector switch. Have attempted to contact Comtek and DX Engineering, where I bought the original, no luck. I need to know the wiring from the control box to the switch.
Dave Kaiser, AL7HG

------------------------------

Message: 3
Date: Thu, 26 Jan 2023 11:27:38 -0600
From: Jim W7RY <jimw7ry at gmail.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Need Comtek manual
Message-ID: <04d2d78a-2578-bcff-9029-102fd072e997 at gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed

Call DX engineering on the phone.

Jim W7RY

On 1/26/2023 11:26 AM, Dave Kaiser via TowerTalk wrote:
>  I am looking for a manual for the Comtek RSV 8 antenna connector switch. Have attempted to contact Comtek and DX Engineering, where I bought the original, no luck. I need to know the wiring from the control box to the switch.
> Dave Kaiser, AL7HG
>
>    
>  
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk

-- 
Thanks and 73, Jim W7RY

------------------------------

Message: 4
Date: Thu, 26 Jan 2023 12:57:16 -0500
From: "Tim Duffy" <k3lr at k3lr.com>
To: "'Dave Kaiser'" <kaiserdr at yahoo.com>,    "reflector -tower"
    <towertalk at contesting.com>
Subject: Re: [TowerTalk] Need Comtek manual
Message-ID: <02a201d931af$a125ff00$e371fd00$@k3lr.com>
Content-Type: text/plain;    charset="us-ascii"

Hello Dave

We will help you 

K8RR will take care of you

Stand by for a response

73
Tim K3LR
CEO DX Engineering

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Dave
Kaiser via TowerTalk
Sent: Thursday, January 26, 2023 12:27 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Need Comtek manual

 I am looking for a manual for the Comtek RSV 8 antenna connector switch.
Have attempted to contact Comtek and DX Engineering, where I bought the
original, no luck. I need to know the wiring from the control box to the
switch.
Dave Kaiser, AL7HG

_______________________________________________

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TowerTalk at contesting.com
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------------------------------

Message: 5
Date: Thu, 26 Jan 2023 13:33:46 -0500
From: Art Greenberg <art at artg.tv>
To: towertalk at contesting.com
Subject: [TowerTalk] Assembling a Yagi
Message-ID: <332ad798-8e07-3fc2-8164-c7b72bc99638 at artg.tv>
Content-Type: text/plain; charset=UTF-8; format=flowed

The instructions for setting element length aren't clear. Do I measure 
from element tip to the side of the boom, or to the center of the boom?

I think its the later ...

TNX

-- 
Art Greenberg
WA2LLN
art at artg.tv

------------------------------

Message: 6
Date: Thu, 26 Jan 2023 13:52:39 -0500
From: Art Greenberg <art at artg.tv>
To: towertalk at contesting.com
Subject: [TowerTalk] Common Mode Choke Locations
Message-ID: <081ca86a-be2d-d304-a762-74b2ff4fefed at artg.tv>
Content-Type: text/plain; charset=UTF-8; format=flowed

I seek a better understanding of the proper application of common mode 
chokes.

First, the setup:

I have several coax-fed antennas on a crank-up tower. The coax shields 
are bonded to the tower at the top of the tower (at the end of the rotor 
loop) and near the bottom of the tower. The bottom of the tower is in 
turn bonded to a fairly extensive lightning ground system. The coax 
leaves the lower bonding point and is bundled with rotor and control 
cables, all of which go under ground in conduit to an entrance panel 
where the coax encounters lightning arrestors mounted on a copper plate. 
There are also lightning arrestors for the rotor and control cables 
mounted on the copper plate. There is also a copper strap that runs 
alongside the conduit to bond the tower to the copper plate. The copper 
plate is bonded to additional ground below it which is also connected to 
the mains ground.

The questions:

I realize that the bonding and lightning ground system isn't an RF 
ground, but I wonder if it influences the location(s) of common mode chokes?

I -think- a CM choke is appropriate at the antenna feedpoint, despite 
the bonding setup. Is that true?

Is an additional CM choke appropriate near the bottom of the tower? On 
which side of the bonding at the bottom of the tower?

Is an additional CM choke appropriate before the lightning arrestor? Or 
between the lightning arrestor and the equipment?

TNX

-- 
Art Greenberg
WA2LLN
art at artg.tv

------------------------------

Message: 7
Date: Thu, 26 Jan 2023 12:57:44 -0800
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Common Mode Choke Locations
Message-ID:
    <871b9770-2fc8-1c0a-7ba0-ab703acfae0a at audiosystemsgroup.com>
Content-Type: text/plain; charset=UTF-8; format=flowed

On 1/26/2023 10:52 AM, Art Greenberg wrote:
> I seek a better understanding of the proper application of common mode 
> chokes.

k9yc.com/publish.htm

Study the "Cookbook" and the Ham's Guide.

73, Jim K9YC

------------------------------

Message: 8
Date: Thu, 26 Jan 2023 16:22:41 -0600
From: Doug Christensen <auriga1usa at gmail.com>
To: Art Greenberg <art at artg.tv>
Cc: towertalk at contesting.com
Subject: Re: [TowerTalk] Assembling a Yagi
Message-ID:
    <CAD4cJu9J6xAPV4yczj_mZL355SgkEUcqxpOcQmHZkyr_+RJsPQ at mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"

>From  center of where the electrical connection starts near the boom, to
where the element terminates at the outside of the array.

doug
wb1e
73

On Thu, Jan 26, 2023, 12:34 PM Art Greenberg <art at artg.tv> wrote:

> The instructions for setting element length aren't clear. Do I measure
> from element tip to the side of the boom, or to the center of the boom?
>
> I think its the later ...
>
> TNX
>
> --
> Art Greenberg
> WA2LLN
> art at artg.tv
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>

------------------------------

Message: 9
Date: Thu, 26 Jan 2023 17:24:50 -0500
From: Art Greenberg <art at artg.tv>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Assembling a Yagi
Message-ID: <860c166e-fdf8-e693-f597-a54d7fbd6bb9 at artg.tv>
Content-Type: text/plain; charset=UTF-8; format=flowed

I think I left out an important detail. Elements are all connected to 
the boom. Even the DE, fed with a "beta" match.

On 1/26/23 17:22, Doug Christensen wrote:
>  From  center of where the electrical connection starts near the boom, to
> where the element terminates at the outside of the array.
> 
> doug
> wb1e
> 73
> 
> On Thu, Jan 26, 2023, 12:34 PM Art Greenberg <art at artg.tv> wrote:
> 
>> The instructions for setting element length aren't clear. Do I measure
>> from element tip to the side of the boom, or to the center of the boom?
>>
>> I think its the later ...
>>
>> TNX
>>
>> --
>> Art Greenberg
>> WA2LLN
>> art at artg.tv
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk

-- 
Art Greenberg
art at artg.tv

------------------------------

Message: 10
Date: Thu, 26 Jan 2023 17:26:37 -0500
From: Art Greenberg <art at artg.tv>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Assembling a Yagi
Message-ID: <5134f1a1-a043-5894-96a7-1323b34536a0 at artg.tv>
Content-Type: text/plain; charset=UTF-8; format=flowed

I should proof read before posting. The DE is insulated from the boom. 
Fed with a beta match. Its a Hy-Gain antenna.

On 1/26/23 17:24, Art Greenberg wrote:
> I think I left out an important detail. Elements are all connected to 
> the boom. Even the DE, fed with a "beta" match.
> 
> 
> On 1/26/23 17:22, Doug Christensen wrote:
>> ?From? center of where the electrical connection starts near the boom, to
>> where the element terminates at the outside of the array.
>>
>> doug
>> wb1e
>> 73
>>
>> On Thu, Jan 26, 2023, 12:34 PM Art Greenberg <art at artg.tv> wrote:
>>
>>> The instructions for setting element length aren't clear. Do I measure
>>> from element tip to the side of the boom, or to the center of the boom?
>>>
>>> I think its the later ...
>>>
>>> TNX
>>>
>>> -- 
>>> Art Greenberg
>>> WA2LLN
>>> art at artg.tv
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
> 

-- 
Art Greenberg
art at artg.tv

------------------------------

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End of TowerTalk Digest, Vol 241, Issue 24
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