Brian breazey element hf beam can't forward dos
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of
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Sent: Thursday, May 13, 2021 6:48 PM
To: towertalk@contesting.com
Subject: TowerTalk Digest, Vol 221, Issue 10
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Contents of TowerTalk digest..."
Today's Topics:
1. Coil Antennas (Brian Beezley)
2. Re: Mystery antenna! Now identified!!! (Tom WA9WSJ)
3. Re: 12V transient/noise filtering? (Jim Brown)
4. Re: 12V transient/noise filtering? (Lux, Jim)
5. Compatible Hardline Connectors (Shawn Donley)
6. Re: 12V transient/noise filtering? (Doug Ronald)
7. Re: 12V transient/noise filtering? (Lux, Jim)
8. Air Dummy Loads (tony.kaz@verizon.net)
9. Re: Air Dummy Loads (Lux, Jim)
10. Re: Air Dummy Loads (KD7JYK DM09)
11. Re: Compatible Hardline Connectors (Steve K8LX)
----------------------------------------------------------------------
Message: 1
Date: Thu, 13 May 2021 10:03:16 -0700
From: Brian Beezley <k6sti@att.net>
To: towertalk@contesting.com
Subject: [TowerTalk] Coil Antennas
Message-ID: <08017a41-9244-fb10-a891-ab4582b96067@att.net>
Content-Type: text/plain; charset=utf-8; format=flowed
I've added a feature to my coil inductance and Q calculator that can help you
evaluate a coil as a multiturn loop antenna. The program calculates reception
factor, a figure proportional to the signal voltage a coil produces when
resonated with a capacitor. You can experiment with coil dimensions to see the
effect on receive signal level. The program can model circular, octagonal,
hexagonal, or square solenoids that use solid or Litz wire.
Originally I used the automatic optimizer that normally maximizes coil Q to
maximize reception factor. However, optimal coils turned out quite long and
used large amounts of wire. Reducing coil length by a large factor often
lowered performance only a dB or two. I'd never want to build one of the
optimal designs so I removed the optimization function.
It's easy to design a suitable receive loop by hand. Bigger is better, but
maximum diameter is limited by practical considerations. Wire size is often
determined by what's on hand or what's economical. That leaves coil length and
number of turns. You can vary each with the mouse wheel and watch the reception
factor change.
Reception factor is useful when you want to minimize reception. For example,
you can first optimize a 160m matching network coil for highest Q and then
adjust it to lower direct pickup. This might help maintain deep nulls in a
directional receiving array or minimize troublesome AM broadcast signals.
Recently I greatly improved program accuracy for very short coils. I also
updated the skin effect and proximity loss calculations so they are good down
to DC. These changes increase accuracy for coils used as low-frequency loop
antennas, especially on the 2200m band.
Windows program:
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fham-radio.com%2Fk6sti%2Fcoil.zip&data=04%7C01%7C%7Cc298fd09a0974bca13e508d916613100%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637565428949792258%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=KGed5LkSPXNzzBKPd6c7RTCSYdlHFnSV%2BNfE1tAkwAc%3D&reserved=0
Reception factor reference:
https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Frudys.typepad.com%2Ffiles%2Fcoil-antennas-1919.pdf&data=04%7C01%7C%7Cc298fd09a0974bca13e508d916613100%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637565428949792258%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=7eXvnD3%2BD5Bo%2BGu%2BIXJlWx%2FL5w83RSfUmDllKVGGJUU%3D&reserved=0
Brian
------------------------------
Message: 2
Date: Thu, 13 May 2021 17:11:30 +0000 (UTC)
From: Tom WA9WSJ <wa9wsj@yahoo.com>
To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Mystery antenna! Now identified!!!
Message-ID: <1058655556.613218.1620925890964@mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8
Hi Dave,
Thank you also for the info!?
I'll keep looking for a manual and go from there.
Great to get all the help from this reflector!!!
73 All!
Tom
On Thursday, May 13, 2021, 09:52:31 AM MDT, Dave Thompson
<thompson@mindspring.com> wrote:
That is the Butternut HF-5 antenna.? I had one in temporary? position and it
does work will as I remember its is a tri-band antenna no 17 or 12.? I thought
it might work well for my St. Simon's Island location but I found it too
gangling so I sold it to another ham and it has worked well for him.
73 Dave K4JRB
-----Original Message-----
>From: Matthew Kaufman <matthew@matthew.at>
>Sent: May 13, 2021 12:22 AM
>To: Tom WA9WSJ <wa9wsj@yahoo.com>
>Cc: Towertalk Reflector <towertalk@contesting.com>
>Subject: Re: [TowerTalk] Mystery antenna!
>
>Relative of a Butternut HF-5B, I do believe. I was thinking Cushcraft
>at first, but Butternut has those spreaders.
>
>On Wed, May 12, 2021 at 8:03 PM Tom WA9WSJ via TowerTalk <
>towertalk@contesting.com> wrote:
>
>> Hello Gents,
>> I have acquired an antenna the like of which I've never seen before!
>> I believe it to be some small hf antenna but ???
>> I posted some pics and additional info on my page here...
>> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.w
>> a9wsj.com%2Fwhat_antenna.htm&data=04%7C01%7C%7Cc298fd09a0974bca13
>> e508d916613100%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637565428
>> 949792258%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzI
>> iLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=nGoKfEsf1CvPe%2FOfC%
>> 2F%2B3Yc81gJncxsvKcm7qvVQ29Fo%3D&reserved=0
>>
>> Can someone please tell me what brand and model etc it is?And of
>> course what it might be worth?
>> Thanks much!!
>> Tom wa9wsj
>>
>>
>> _______________________________________________
>>
>>
>>
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>> zBzV3bz2iMC%2BQCXM76SyLvfp%2FBhwOawIAmcUkFZvETA%3D&reserved=0
>>
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------------------------------
Message: 3
Date: Thu, 13 May 2021 10:42:58 -0700
From: Jim Brown <jim@audiosystemsgroup.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 12V transient/noise filtering?
Message-ID:
<518cb298-7631-5850-6d7d-1e1c31c8b166@audiosystemsgroup.com>
Content-Type: text/plain; charset=utf-8; format=flowed
On 5/12/2021 7:39 PM, Michael Tope wrote:
> You would have to dive into the EMI/EMC specs provided in the
> datasheet
> - in particular conducted susceptibility
In my experience, most EMI is common mode, and is not accurately described on
data sheets.
73, Jim K9YC
------------------------------
Message: 4
Date: Thu, 13 May 2021 13:29:25 -0700
From: "Lux, Jim" <jim@luxfamily.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 12V transient/noise filtering?
Message-ID: <7cbc3606-269c-417a-d9a6-5080cc591353@luxfamily.com>
Content-Type: text/plain; charset=utf-8; format=flowed
On 5/13/21 10:42 AM, Jim Brown wrote:
> On 5/12/2021 7:39 PM, Michael Tope wrote:
>> You would have to dive into the EMI/EMC specs provided in the
>> datasheet - in particular conducted susceptibility
>
> In my experience, most EMI is common mode, and is not accurately
> described on data sheets.
but here, I'm not looking at EMI - I'm concerned about differential mode
transients (inductive things like relay coils, etc.) blowing up the
other things in the circuit.? Things like having a USB interface - they
tend not to like big transients, and I'd rather not blow up the laptop,
or Raspberry Pi, etc.? Sure, they have some sort of voltage regulator
that brings 12V down to 3.3 or 5V, but things like the venerable 7805
have a 35V absolute max so that 50V transient will kill it.
A DC/DC converter like those from CUI might have a wide range input, but
probably not 50V and they have no reverse protection.
Something like a reverse biased 20V Zener might actually solve my problems.
------------------------------
Message: 5
Date: Thu, 13 May 2021 16:36:47 -0400 (EDT)
From: Shawn Donley <n3ae@comcast.net>
To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: [TowerTalk] Compatible Hardline Connectors
Message-ID: <885173726.216434.1620938208339@connect.xfinity.com>
Content-Type: text/plain; charset=UTF-8
I have several Cablewave 738801 Type-N female connectors for FCL12-50 cable.
Anyone know if these connectors can go on to Andrew LDF4-50A cable as well?
I'd love to find a matrix of hardline cable types and compatible connectors but
have never run across one.
tnx N3AE
------------------------------
Message: 6
Date: Thu, 13 May 2021 14:01:58 -0700
From: "Doug Ronald" <doug@dougronald.com>
To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] 12V transient/noise filtering?
Message-ID: <000c01d7483b$36d99b20$a48cd160$@dougronald.com>
Content-Type: text/plain; charset="UTF-8"
It seems like a Maxim MAX16171 would fit the bill. It handles an input
protection range of -42 through +76 V, and with an external FET, any reasonable
current you need. I didn't look into an application board, but Maxim usually
has those for its products. Even if you rolled your own, there are only a few
components needed...
-Doug, W6DSR
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Lux, Jim
Sent: Thursday, May 13, 2021 13:29
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 12V transient/noise filtering?
On 5/13/21 10:42 AM, Jim Brown wrote:
> On 5/12/2021 7:39 PM, Michael Tope wrote:
>> You would have to dive into the EMI/EMC specs provided in the
>> datasheet - in particular conducted susceptibility
>
> In my experience, most EMI is common mode, and is not accurately
> described on data sheets.
but here, I'm not looking at EMI - I'm concerned about differential mode
transients (inductive things like relay coils, etc.) blowing up the
other things in the circuit. Things like having a USB interface - they
tend not to like big transients, and I'd rather not blow up the laptop,
or Raspberry Pi, etc. Sure, they have some sort of voltage regulator
that brings 12V down to 3.3 or 5V, but things like the venerable 7805
have a 35V absolute max so that 50V transient will kill it.
A DC/DC converter like those from CUI might have a wide range input, but
probably not 50V and they have no reverse protection.
Something like a reverse biased 20V Zener might actually solve my problems.
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------------------------------
Message: 7
Date: Thu, 13 May 2021 14:08:49 -0700
From: "Lux, Jim" <jim@luxfamily.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 12V transient/noise filtering?
Message-ID: <675e40f8-bda5-9e8a-d3f6-941f0678b0af@luxfamily.com>
Content-Type: text/plain; charset=utf-8; format=flowed
On 5/13/21 2:01 PM, Doug Ronald wrote:
> It seems like a Maxim MAX16171 would fit the bill. It handles an input
> protection range of -42 through +76 V, and with an external FET, any
> reasonable current you need. I didn't look into an application board, but
> Maxim usually has those for its products. Even if you rolled your own, there
> are only a few components needed...
> -Doug, W6DSR
Interesting part - it drives a series FET to make a "virtual ideal
diode" - and it's intended for automotive applications..
Evalboard for $73
------------------------------
Message: 8
Date: Thu, 13 May 2021 22:08:27 +0000 (UTC)
From: tony.kaz@verizon.net
To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: [TowerTalk] Air Dummy Loads
Message-ID: <833660391.379803.1620943707934@mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8
It is time to get rid of my 50+ year old Heathkit oil paint can dummy load.I
want to mount a 1500W (intermittent) dummy load vertically on my ground panel
in the basement.I am not interested in the dummy loads that have a fan that
runs all the time.The Palstar DL1500 looks nice because it is set up to mount
to a panel - $200..But the MFJ-264 and Vectronic DL-650M are only $90. What do
you get for the extra $110 for the Palstar?Tnx for any feedbackN2TK, Tony
------------------------------
Message: 9
Date: Thu, 13 May 2021 15:27:02 -0700
From: "Lux, Jim" <jim@luxfamily.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Air Dummy Loads
Message-ID: <4fad0ea7-1548-e8ee-1cd8-0396ec2aac70@luxfamily.com>
Content-Type: text/plain; charset=utf-8; format=flowed
On 5/13/21 3:08 PM, tony.kaz--- via TowerTalk wrote:
> It is time to get rid of my 50+ year old Heathkit oil paint can dummy load.I
> want to mount a 1500W (intermittent) dummy load vertically on my ground panel
> in the basement.I am not interested in the dummy loads that have a fan that
> runs all the time.The Palstar DL1500 looks nice because it is set up to mount
> to a panel - $200..But the MFJ-264 and Vectronic DL-650M are only $90. What
> do you get for the extra $110 for the Palstar?Tnx for any feedbackN2TK, Tony
> _______________________________________________
The MFJ is 1.5kW for 10 seconds, 100W for 10 mins.? Seems to be the same
as the MFJ.? The palstar is in a gold iridite case - The MFJ is in MFJ
flat black?
Probably not a huge difference.
------------------------------
Message: 10
Date: Thu, 13 May 2021 15:28:43 -0700
From: KD7JYK DM09 <kd7jyk@earthlink.net>
To: tony.kaz@verizon.net, "towertalk@contesting.com"
<towertalk@contesting.com>
Subject: Re: [TowerTalk] Air Dummy Loads
Message-ID: <3d0e24e9-b014-b649-d86d-358483d52e6a@earthlink.net>
Content-Type: text/plain; charset=utf-8; format=flowed
I bought an MFJ-264 years ago. The resistance was something like 20
some-odd Ohms (for some reason 17 Ohms just popped into my head, so
maybe that was it), and there were various issues inside, missed solder
joints, cold joints, burned joints, and solder bridges. It was total
crap. Some may be better, some may be worse, but the one I bought was
in this condition, new, from MFJ. Inside views of the Palstar model
indicate one big load, this may prevent some issues as it's simple, so
based on internal appearance alone, I'd go with that. I didn't see any
inside pics of the Vectronics model, but it looks like an unpainted, and
relabeled MFJ.
Kurt
------------------------------
Message: 11
Date: Thu, 13 May 2021 18:47:45 -0400
From: Steve K8LX <lists@oakcom.org>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Compatible Hardline Connectors
Message-ID: <e5727a5a-b215-42d5-958d-8778dcefd02e@oakcom.org>
Content-Type: text/plain; charset=utf-8; format=flowed
You probably mean LCF12-50.
The big issue with mating connectors and cables from different
manufacturers is the center conductor diameter/design.
LCF12-50 & LDF4-50 are both 1/2" annular corrugated cables so the shield
will be almost identical.
Depending on the dielectric, the center conductor might vary in diameter
a little bit. Some connectors can accept a little variation in center
conductor diameter and still make good contact.
Extract a piece of LDF4 center conductor and push it in to the RFS
center pin. Does it feel firm? If so, you should be good to go.
-Steve K8LX
On 5/13/2021 4:36 PM, Shawn Donley wrote:
> I have several Cablewave 738801 Type-N female connectors for FCL12-50 cable.
> Anyone know if these connectors can go on to Andrew LDF4-50A cable as well?
>
> I'd love to find a matrix of hardline cable types and compatible connectors
> but have never run across one.
>
> tnx N3AE
>
> _______________________________________________
>
>
>
> _______________________________________________
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