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Brett Howard

Coax Loss Figures

I'm trying to find the specs on this chunk of coax that has the RP-TNC
connectors on it... I'm not having a lot of luck but perhaps someone is
more familar with it than I... Its just says Amphenol TWO 6001 9G

Then the box just says its a Cisco Systems Ultra Low Loss Coax
Assembly... And being Cisco is why I get the joy of dealing with the
RP-TNC... ;) But hey the whole thing was free!

~Brett

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n7ws

Re: Coax Loss Figures

Ultra low loss is meaningless. What is the diameter?

I've been out of the industry for some time, but as I recall Amphenol didn't make bulk cable, so they likely bought the cable from Belden, Times, etc and built a cable assembly for Cisco.

I think your original premise is flawed. If you want to move the match point of a 43' vertical 100' into your shack you probably should be looking for some 7/8" Helix.

Wes N7WS

--- On Tue, 6/22/10, Brett Howard <[hidden email]> wrote:

From: Brett Howard <[hidden email]>
Subject: [Elecraft] Coax Loss Figures
To: "elecraft" <[hidden email]>
Date: Tuesday, June 22, 2010, 9:16 PM

I'm trying to find the specs on this chunk of coax that has the RP-TNC
connectors on it... I'm not having a lot of luck but perhaps someone is
more familar with it than I... Its just says Amphenol TWO 6001 9G

Then the box just says its a Cisco Systems Ultra Low Loss Coax
Assembly... And being Cisco is why I get the joy of dealing with the
RP-TNC... ;) But hey the whole thing was free!

~Brett

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Brett Howard

Re: Coax Loss Figures

I think I found a sheet that says its "LMR600" or at least its in a
grouping that makes me think it might be LMR600.

OD on the stuff is .591 by my measurements.

>From my calculation a 5:1 mismatch on 100 feet of LMR-400 would still
get me 75watts out the antenna at 30Mhz and things only get better as I
head down into 20 and 40 meters.

~Brett (N7MG)

On Tue, 2010-06-22 at 20:51 -0700, Wes Stewart wrote:
> loss is meaningless. What is the diameter?
>
> I've been out of the industry for some time, but as I recall Amphenol
> didn't make bulk cable, so they likely bought the cable from Belden,
> Times, etc and built a cable assembly for Cisco.
>
> I think your original premise is flawed. If you want to move the
> match point of a 43' vertical 100' into your shack you probably should
> be looking for some 7/8" Helix.

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Phil Kane-2

Re: Coax Loss Figures

On 6/22/2010 8:55 PM, Brett Howard wrote:

> From my calculation a 5:1 mismatch on 100 feet of LMR-400 would
> still get me 75watts out the antenna at 30Mhz and things only get
> better as I head down into 20 and 40 meters.

On that basis, see if you can get some 75 ohm "hardline" from
your local cable company - they are pulling it all out in favor of
fiber optic cable and throwing it away unless the local hams
ask for it. We have several hams here who use that to go up
70-100 foot towers and get out very well despite the apparent
mismatch.

-- 73 de K2ASP - Phil Kane
Elecraft K2/100 s/n 5402

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Bob Cunnings NW8L

Re: Coax Loss Figures

In reply to this post by Brett Howard

In Cisco parlance, "Low Loss" and "Ultra Low Loss" refers to classes
of "Aironet" coax cable assemblies. On this data sheet:

http://tinyurl.com/yr8fck

we find these described in Table 8. If you indeed have part nbr
"AIR-CAB100ULL-R" (where the ULL means Ultra Low Loss) then the
attenuation is specified as 4.4 dB per 100 ft at 2.4 GHz. This puts it
in the LMR600 class, < 0.5 dB attenuation per 100 ft at 30 MHz.

Bob NW8L

On Tue, Jun 22, 2010 at 9:16 PM, Brett Howard <[hidden email]> wrote:

> I'm trying to find the specs on this chunk of coax that has the RP-TNC
> connectors on it... I'm not having a lot of luck but perhaps someone is
> more familar with it than I... Its just says Amphenol TWO 6001 9G
>
> Then the box just says its a Cisco Systems Ultra Low Loss Coax
> Assembly... And being Cisco is why I get the joy of dealing with the
> RP-TNC... ;) But hey the whole thing was free!
>
> ~Brett
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
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Brett Howard

Re: Coax Loss Figures

In reply to this post by Phil Kane-2

I know I'm about to sound completely nuts to everyone but I'm just doing
all this stuff for FD... ;)

I'll probably end up using the 100' or 50' chunk of LMR400 that I have
laying around here depending on how far away the antenna has to be from
the tent... Being that I'm going to be running 40 radials (and don't
want to staple it down) I'm going to need to keep it away from where
people will be walking.

I've also got 2 other wire antennas that are proven and we know are
going to work well... But I always like trying stuff that I've never
done before for FD. I know we're not going to be winning any awards but
I've got trees freakin everywhere and I'm going to probably have 4
antennas hooked to the K3 two RX only and two TX/RX...

I've never been to the location where its held this year and so thats
new for me too. I just try to have fun, make sure I get a few good
bites of the potluck, and get to play with more antennas and better
antennas than I'll ever have at my current home. Later I'll have a
better setup but for now FD is my biggest play date w/ Ham Radio every
year...

These are where I get to try stupid things and find out what does and
doesn't work.

~Brett (N7MG)

~Brett (N7MG)

On Tue, 2010-06-22 at 21:10 -0700, Phil Kane wrote:
> On that basis, see if you can get some 75 ohm "hardline" from
> your local cable company - they are pulling it all out in favor of
> fiber optic cable and throwing it away unless the local hams
> ask for it. We have several hams here who use that to go up
> 70-100 foot towers and get out very well despite the apparent
> mismatch.

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Brett Howard

Re: Coax Loss Figures

In reply to this post by Bob Cunnings NW8L

Thats another really great data point! Knowing Cisco getting the word
ultra printed on the box cost a good chunk of extra change! ;)

Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking
with finding adapters for it as if I end up having to put 2 adapters on
each end to get it to something I can use there goes most of my
advantage of stepping up from LMR400 to LMR600...

~Brett

On Tue, 2010-06-22 at 22:19 -0600, Bob Cunnings wrote:

> In Cisco parlance, "Low Loss" and "Ultra Low Loss" refers to classes
> of "Aironet" coax cable assemblies. On this data sheet:
>
> http://tinyurl.com/yr8fck
>
> we find these described in Table 8. If you indeed have part nbr
> "AIR-CAB100ULL-R" (where the ULL means Ultra Low Loss) then the
> attenuation is specified as 4.4 dB per 100 ft at 2.4 GHz. This puts it
> in the LMR600 class, < 0.5 dB attenuation per 100 ft at 30 MHz.
>
> Bob NW8L
>
> On Tue, Jun 22, 2010 at 9:16 PM, Brett Howard <[hidden email]> wrote:
> > I'm trying to find the specs on this chunk of coax that has the RP-TNC
> > connectors on it... I'm not having a lot of luck but perhaps someone is
> > more familar with it than I... Its just says Amphenol TWO 6001 9G
> >
> > Then the box just says its a Cisco Systems Ultra Low Loss Coax
> > Assembly... And being Cisco is why I get the joy of dealing with the
> > RP-TNC... ;) But hey the whole thing was free!
> >
> > ~Brett
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> ______________________________________________________________
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Jim Brown-10

Re: Coax Loss Figures

In reply to this post by Brett Howard

Check out

http://audiosystemsgroup.com/Coax-Stubs.pdf

100 ft of almost any decent RG8-size or RG11-size coax is just fine for a
Field Day antenna on the HF bands. On the lower HF bands, RG8X-size coax is
just fine.

73, Jim K9YC

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W8JI

Re: Coax Loss Figures

In reply to this post by Brett Howard

> Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking
> with finding adapters for it as if I end up having to put 2 adapters on
> each end to get it to something I can use there goes most of my
> advantage of stepping up from LMR400 to LMR600...

The loss in connectors or adaptors at HF or even up into VHF is virtually
immeasurable, unless they are simply terrible. If the connectors are
terrible you might have 0.05 dB loss.

A common SO-239/PL259 junction has less than .02 dB loss at upper HF.

I'd be more concerned with transmission line losses due to SWR on the
transmission line and voltage breakdown of connectors in your application.
Here are the peak voltages at the antenna base with only 100 watts applied
at the antenna, and the losses in a feedline using 100 feet of LMR500:

160= 4800v (>100:1 SWR) 16 dB feedline loss
80 = 1000v (>100:1 SWR) 6 dB feedline loss
40 = 215v (5.4:1 SWR) .6 dB feedline loss
30 = 500v (26:1 SWR) 3 dB feedline loss
20 = 540v (29:1 SWR) 3.5 dB feedline loss
15 = 280v (9:1 SWR) 1.7 dB feedline loss

Why would you worry about connectors when 100 feet of LMR500 would have
losses like that? Put a tuner at the antenna base if you want to reduce
losses.

73 Tom

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Brett Howard

Re: Coax Loss Figures

In reply to this post by Jim Brown-10

Yea I know I'm going way overkill and I was doing all the calculations
by hand of total loss and at a 7:1 SWR (which is entirely possible on
this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not
modeled it fully but on all bands but on 20 meters its 7:1 and on 40
meters its 3:1...

I think I'm just going to call it a day and use the LMR400... But its
fun to overthink this stuff... Article looks nice I can see I'm going
to be up for a few more minutes! ;)

~Brett (N7MG)

On Tue, 2010-06-22 at 23:34 -0700, Jim Brown wrote:

> Check out
>
> http://audiosystemsgroup.com/Coax-Stubs.pdf
>
> 100 ft of almost any decent RG8-size or RG11-size coax is just fine for a
> Field Day antenna on the HF bands. On the lower HF bands, RG8X-size coax is
> just fine.
>
> 73, Jim K9YC
>
>
> ______________________________________________________________
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Brett Howard

Re: Coax Loss Figures

In reply to this post by W8JI

I was starting to look at connectors when comparing getting adapters to
use the LMR600 that I have to that of using LMR400 that I have with the
right connectors on it already...

>From what I've seen in other models I'm expecting 7:1 SWR on 20 and 3:1
SWR on 40 with the 4:1 UNUN that DX recommends to help make things tune
easier.

When Elecraft makes me a remotable tuner that will work with my setup
then I'm game... Till then I'll suffice with the tuner thats built into
the radio. It should be able to handle most of what I should see with
that 4:1UNUN on there and its capability of tuning things w/in 10:1...
I'm not holding my breath for using it on 80Meters but we'll see what
the tuner can handle... I plan on setting things up on Friday and
taking my notebook and collecting a bunch of data on it to see how
things shake out...

I'm not expecting magic I'm just trying to get my head around all the
math and get an idea of what I should expect so I know when to be
surprised and ask questions when reality doesn't match theory... ;)

~Brett (N7MG)

On Wed, 2010-06-23 at 03:15 -0400, Tom W8JI wrote:

> > Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking
> > with finding adapters for it as if I end up having to put 2 adapters on
> > each end to get it to something I can use there goes most of my
> > advantage of stepping up from LMR400 to LMR600...
>
> The loss in connectors or adaptors at HF or even up into VHF is virtually
> immeasurable, unless they are simply terrible. If the connectors are
> terrible you might have 0.05 dB loss.
>
> A common SO-239/PL259 junction has less than .02 dB loss at upper HF.
>
> I'd be more concerned with transmission line losses due to SWR on the
> transmission line and voltage breakdown of connectors in your application.
> Here are the peak voltages at the antenna base with only 100 watts applied
> at the antenna, and the losses in a feedline using 100 feet of LMR500:
>
> 160= 4800v (>100:1 SWR) 16 dB feedline loss
> 80 = 1000v (>100:1 SWR) 6 dB feedline loss
> 40 = 215v (5.4:1 SWR) .6 dB feedline loss
> 30 = 500v (26:1 SWR) 3 dB feedline loss
> 20 = 540v (29:1 SWR) 3.5 dB feedline loss
> 15 = 280v (9:1 SWR) 1.7 dB feedline loss
>
> Why would you worry about connectors when 100 feet of LMR500 would have
> losses like that? Put a tuner at the antenna base if you want to reduce
> losses.
>
> 73 Tom
>

Pete Smith N4ZR

Re: Coax Loss Figures

In reply to this post by Brett Howard

This reflector has more off-topic posts than any I've ever been involved
with. Perhaps the solution (other than the delete key) would be for
people not to reply.

73, Pete N4ZR

The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com,
spots at telnet.reversebeacon.net, port 7000

On 6/23/2010 3:19 AM, Brett Howard wrote:

> Yea I know I'm going way overkill and I was doing all the calculations
> by hand of total loss and at a 7:1 SWR (which is entirely possible on
> this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not
> modeled it fully but on all bands but on 20 meters its 7:1 and on 40
> meters its 3:1...
>
> I think I'm just going to call it a day and use the LMR400... But its
> fun to overthink this stuff... Article looks nice I can see I'm going
> to be up for a few more minutes! ;)
>
> ~Brett (N7MG)
>
> On Tue, 2010-06-22 at 23:34 -0700, Jim Brown wrote:
>
>> Check out
>>
>> http://audiosystemsgroup.com/Coax-Stubs.pdf
>>
>> 100 ft of almost any decent RG8-size or RG11-size coax is just fine for a
>> Field Day antenna on the HF bands. On the lower HF bands, RG8X-size coax is
>> just fine.
>>
>> 73, Jim K9YC
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
> ______________________________________________________________
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>
>
>

Samuel Strongin

Re: Coax Loss Figures

In reply to this post by Phil Kane-2

Let me see spend $4000.00 on a radio So you can hear better, argue over
fine points in the receiver, and THEN go out and get junk cable so you can
save $50.00 . I just can't see the logic.
Sam kf4yox

--------------------------------------------------
From: "Phil Kane" <[hidden email]>
Sent: Wednesday, June 23, 2010 12:10 AM
To: "Brett Howard" <[hidden email]>
Cc: "elecraft" <[hidden email]>
Subject: Re: [Elecraft] Coax Loss Figures

> On 6/22/2010 8:55 PM, Brett Howard wrote:
>
>> From my calculation a 5:1 mismatch on 100 feet of LMR-400 would
>> still get me 75watts out the antenna at 30Mhz and things only get
>> better as I head down into 20 and 40 meters.
>
> On that basis, see if you can get some 75 ohm "hardline" from
> your local cable company - they are pulling it all out in favor of
> fiber optic cable and throwing it away unless the local hams
> ask for it. We have several hams here who use that to go up
> 70-100 foot towers and get out very well despite the apparent
> mismatch.
>
> -- 73 de K2ASP - Phil Kane
> Elecraft K2/100 s/n 5402
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
>

Brett Howard

Re: Coax Loss Figures

Its called field day and I'm trying to get some of the best stuff I can...
I'm having fun with it and learning more all the time. Why not help people
setup their own experiences and enjoy the hobby rather than telling them
that they are simply doing it wrong. If you were stuck in the woods and all
you had was two pieces of wire and a K3 would you use the two together and
save your life or would you never connect the two because you don't have any
expensive feedline and die there?

Personally I spent the money on my radio cause I was allowed to build it and
learn from it. I also get better support. True diversity with equal quality
receivers as I plan on using the vertical with diversity RX. I also get a
UI that I am familue with and find inruitive. Last I checked using LMR400
or LMR600 for a 100 watt FD station is at least someone making an attempt.

This is a hobby guys. I'm just trying to enjoy it...

~Brett. (N7MG)

On Jun 23, 2010 4:21 AM, "Samuel Strongin" <[hidden email]> wrote:
Let me see spend $4000.00 on a radio So you can hear better, argue over
fine points in the receiver, and THEN go out and get junk cable so you can
save $50.00 . I just can't see the logic.
Sam kf4yox

--------------------------------------------------
From: "Phil Kane" <[hidden email]>
Sent: Wednesday, June 23, 2010 12:10 AM
To: "Brett Howard" <[hidden email]>
Cc: "elecraft" <[hidden email]>

Subject: Re: [Elecraft] Coax Loss Figures

> > On 6/22/2010 8:55 PM, Brett Howard wrote:
> >
> >> From my calculation a 5:1 mismatch on 100 feet of L...
>
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: htt...
>
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N5GE

Re: Coax Loss Figures

In reply to this post by Brett Howard

On Wed, 23 Jun 2010 00:19:03 -0700, Brett Howard
<[hidden email]> wrote:

Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as
you can see by the figures, Tom, W8JI, gives you in his post showing
feedline loss and SWR.

During FD you are going to get most of your points from QSO's within
the U.S.A., so put up a 40m ground plane at eight feet on a 4X4 wooden
post in a two foot hole with 4 radials (you can use the radials to guy
the wooden post). 40m is a good band for day and night and is only 32
feet or so tall plus eight feet of post. By doing this you will have
a resonant antenna that will cover 360 degrees at ranges within the
U.S.A.

Adjust the length of your 43 ft vertical by removing the top ten feet
and adjusting it for the end of 40m that you are going to work or set
it in the middle of the band and attach it to the post.

Tom, N5GE
Licensed since 1976
QCWA Life Member 35102

[hidden email]
http://www.n5ge.com
http://www.swotrc.net

>Yea I know I'm going way overkill and I was doing all the calculations
>by hand of total loss and at a 7:1 SWR (which is entirely possible on
>this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not
>modeled it fully but on all bands but on 20 meters its 7:1 and on 40
>meters its 3:1...
[snip]

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Amateur Radio Operator N5GE

Brett Howard

Re: Coax Loss Figures

This is definately something I plan on trying but first I'm going to use it
as intended and record results to see how they match with what I'm told and
what I read... For me its not about the score its about new things to try
and more data to capture and understand. I think overcoming the problems of
this setup in many different ways will keep me busy for at least 5 more
field days. To me that's good fun! Reminds me of the way my late
grandfather was and helps me feel closer to the old man that got me into the
hobby in the first place. I only wish I could still share it with him today.

~Brett (N7MG)

On Jun 23, 2010 7:22 AM, "Radio Amateur N5GE" <[hidden email]> wrote:

> On Wed, 23 Jun 2010 00:19:03 -0700, Brett Howard
> <[hidden email]> wrote:
>
> Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as
> you can see by the figures, Tom, W8JI, gives you in his post showing
> feedline loss and SWR.
>
> During FD you are going to get most of your points from QSO's within
> the U.S.A., so put up a 40m ground plane at eight feet on a 4X4 wooden
> post in a two foot hole with 4 radials (you can use the radials to guy
> the wooden post). 40m is a good band for day and night and is only 32
> feet or so tall plus eight feet of post. By doing this you will have
> a resonant antenna that will cover 360 degrees at ranges within the
> U.S.A.
>
> Adjust the length of your 43 ft vertical by removing the top ten feet
> and adjusting it for the end of 40m that you are going to work or set
> it in the middle of the band and attach it to the post.
>
> Tom, N5GE
> Licensed since 1976
> QCWA Life Member 35102
>
> [hidden email]
> http://www.n5ge.com
> http://www.swotrc.net
>
>>Yea I know I'm going way overkill and I was doing all the calculations
>>by hand of total loss and at a 7:1 SWR (which is entirely possible on
>>this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not
>>modeled it fully but on all bands but on 20 meters its 7:1 and on 40
>>meters its 3:1...
> [snip]
>
> ______________________________________________________________
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Phil Salas

Re: Coax Loss Figures

In reply to this post by N5GE

"...Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as
you can see by the figures, Tom, W8JI, gives you in his post showing
feedline loss and SWR...."

With a 1:4 unun at the base of the antenna, the VSWR from 40-10 meters is
not bad - resulting in minimal coax losses. However, the VSWR on 80 and 160
meters with or without the unun is terrible, and you should match the
antenna at the base on those bands. See the "Articles" section at
www.ad5x.com for 160/80 meter matching ideas.

Phil - AD5X

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Brett Howard

Re: Coax Loss Figures

Actually I did one better... I found a great power point presentation
and read that whole thing... Really dug being able to see the SWR
plot that you had in there and that gave me a lot more confidence that
I was going to be able to use my internal ATU in the K3 to get enough
swing to get the job done. I'm not expecting to get much of anything
below 40. I may try it but only to collect some information and write
up what I find and store it away for the well in a pinch that can
kinda work or don't even try... I do plan on building something
similar to what you'd shown for doing 160 and 80 just to say I've
built one and to make the setup that much more versatile should the
need arise to get on the low bands.

Looking forward to setting it up and collecting information then
getting to do some comparisons between the 43 ft vertical and the
Carolina windom which I'll be using together for diversity. Then I'll
have one other wire up for RX only... I love having options! ;) My
home station is such a compromise that the compromise situation that I
get to play with on FD is just a pure joy! Not to mention that new
locations also make it fun and interesting.

Thanks much for all your information on the 43 ft vertical! I've
found it quite informative and it gives me good information to go on
to make sure things are coming out how I want.

The plan is to feed it w/ 100 ft of LMR 400 or 50 ft of 9913 depending
on how far away we have to put it and which gives us the best results
if both are an option.

~Brett (N7MG)

On Wed, Jun 23, 2010 at 9:43 AM, Phil & Debbie Salas <[hidden email]> wrote:

> "...Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as
> you can see by the figures, Tom, W8JI, gives you in his post showing
> feedline loss and SWR...."
>
> With a 1:4 unun at the base of the antenna, the VSWR from 40-10 meters is
> not bad - resulting in minimal coax losses. However, the VSWR on 80 and 160
> meters with or without the unun is terrible, and you should match the
> antenna at the base on those bands. See the "Articles" section at
> www.ad5x.com for 160/80 meter matching ideas.
>
> Phil - AD5X
>
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N5GE

Re: Coax Loss Figures

In reply to this post by Phil Salas

On Wed, 23 Jun 2010 11:43:30 -0500, "Phil & Debbie Salas"
<[hidden email]> wrote:

See below...

But a 43 foot vertical is resonant at about 5.441MHz. That is nowhere
near any ham band you could use on FD, except 6m using the tenth
harmonic. Matching an antenna's feed point impedance doesn't change
it's point of resonance.

Any how, this thread is way off topic, since it's subject is not an
Elecraft product. Those of you who want to continue this thread,
let's do it with direct emails instead of the reflector.

Tom, N5GE
Licensed since 1976
QCWA Life Member 35102

[hidden email]
http://www.n5ge.com
http://www.swotrc.net

[snip]

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Amateur Radio Operator N5GE