Best coax for aircraft radios

If you would like to have the finest low-loss, light-weight coax cable
for your aircraft radio installations, get Andrew FSJ1-50A Heliax
Superflexible Foam Cable. It's pricier than the RG's, but the
performance is so far superior that your com, VOR, Xpndr, and whatever
will give you range performance like you've never seen. Andrew also has
a matching BNC male connector, the F1PBM. The cable is rated at 6.4kW
peak power, minimum bend radius of 1", and 0.54 oz/ft. Compare that to
RG58 at 0.35oz/ft. It is 0.29" OD, whereas RG58 is o.116" Isolation or
leakage is at least 300dB due to the solid outer jacket, vs 45dB at
best for RG58, and more likely 25dB after being flexed around. Anyone
who uses an RG cable in their aircraft with this stuff available
doesn't really care about good radio rx/tx! Check out their catalog
pages on www.andrew.com .

ELIPPSE wrote:

If you would like to have the finest low-loss, light-weight coax cable
for your aircraft radio installations, get Andrew FSJ1-50A Heliax
Superflexible Foam Cable. It's pricier than the RG's, but the
performance is so far superior that your com, VOR, Xpndr, and whatever
will give you range performance like you've never seen. Andrew also has
a matching BNC male connector, the F1PBM. The cable is rated at 6.4kW
peak power, minimum bend radius of 1", and 0.54 oz/ft. Compare that to
RG58 at 0.35oz/ft. It is 0.29" OD, whereas RG58 is o.116" Isolation or
leakage is at least 300dB due to the solid outer jacket, vs 45dB at
best for RG58, and more likely 25dB after being flexed around. Anyone
who uses an RG cable in their aircraft with this stuff available
doesn't really care about good radio rx/tx! Check out their catalog
pages on www.andrew.com .


Between this and the props . . . .

Hey man this isn't rec.aviation.marketing!

UltraJohn wrote:

ELIPPSE wrote:

If you would like to have the finest low-loss, light-weight coax cable
for your aircraft radio installations, get Andrew FSJ1-50A Heliax
Superflexible Foam Cable. It's pricier than the RG's, but the
performance is so far superior that your com, VOR, Xpndr, and whatever
will give you range performance like you've never seen. Andequipmentas
a matching BNC male connector, the F1PBM. The cable is rated at 6.4kW
peak power, minimum bend radius of 1", and 0.54 oz/ft. Compare that to
RG58 at 0.35oz/ft. It is 0.29" OD, whereas RG58 is o.116" Isolation or
leakage is at least 300dB due to the solid outer jacket, vs 45dB at
best for RG58, and more likely 25dB after being flexed around. Anyone
who uses an RG cable in their aircraft with this stuff available
doesn't really care about good radio rx/tx! Check out their catalog
pages on www.andrew.com .


Between this and the props . . . .

Hey man this isn't rec.aviation.marketing!
Replying tomy own!
It was mainly meant for the other posts he sent at the same time touting the
same prop in an obvious marketing ploy.

Now as far as the cable goes. Hey at lest than 20 feet for most runs you
don't need heliax and actually 58 is usable for most. There are plenty of
better than 58 available locally such as some of the micro rg8's. also as
you stated your heliax is twice+ the size so that can be a concern and also
your quote of 300db. . well I can't prove otherwise but I doubt it. In any
case the equipment and connectors you use it with has so much more leakage
than that that it would be overkill if it did have 300db isolation. Lastly
who needs cable rated at 6.4kw for transmitters running 5 watt (comms) to
maybe a couple hundred (transponders)?
Anyway I'm sure its great cable, Andrews is a very reputable company but it
is way overkill for most homebuilders!
John

Andrew Heliax is fine cable - just what you need to run
up a tower (it comes in many sizes). But in an airplane?
Like the man said - it's overkill. I'd recommend RG142.

As for the isolation - engineers have an inside joke that
goes something like this:

Oh say can you see.....
Three Hundred Dee Bee....

This is a range greater than that between the smallest
detectable signal to an unimaginable amount of power.
In other words, it doesn't exist in the natural world.
AFAIK, nobody makes anything with "300 dB of isolation".
Any engineers out there who would care to comment?

David Johnson

wrote:
Andrew Heliax is fine cable - just what you need to run
up a tower (it comes in many sizes). But in an airplane?
Like the man said - it's overkill. I'd recommend RG142.

As for the isolation - engineers have an inside joke that
goes something like this:

Oh say can you see.....
Three Hundred Dee Bee....

This is a range greater than that between the smallest
detectable signal to an unimaginable amount of power.
In other words, it doesn't exist in the natural world.
AFAIK, nobody makes anything with "300 dB of isolation".
Any engineers out there who would care to comment?

David Johnson

I used to work with andrews 3 1/8 coax for broadcast stations. With 25kw
input there is almost no measurable radiation from the cable. Andrews
uses a SOLID copper outer jacket that is far superior to any foil or
braid jacketed cable. But for RG58 in a 10 foot cable a 1db loss is very
minor. Larsen antennas does sell a RG58 low loss cable, mainly used for
cellular service.

I missed the original post, so...

What was the original poster's concern about isolation? I'm not aware
of any repeaters in use aboard aircraft. Is he worried about signals
leaking out of the coax of say com1 transmitting and getting into the
receiver of com2? I wouldn't think there would be much need to
worry...more RF will get into the com2 receiver by the RF leaving the
antenna. Seems to me that no matter what kind of "isolation" the coax
cable has, the worst thing that can happen is that he would experience a
little desense on com2 receive while he's transmitting on com1, but it
wouldn't make too much difference...if he's talking on com1, he won't be
able to concentrate too much on what is being received on com2 anyway...

RG-142 is nice cable, but it's not quite as flexible as RG58. The loss
in 10 or 20 feet of RG58 isn't really worth the extra cost in my opinion...

Scott

wrote:
Andrew Heliax is fine cable - just what you need to run
up a tower (it comes in many sizes). But in an airplane?
Like the man said - it's overkill. I'd recommend RG142.

As for the isolation - engineers have an inside joke that
goes something like this:

Oh say can you see.....
Three Hundred Dee Bee....

This is a range greater than that between the smallest
detectable signal to an unimaginable amount of power.
In other words, it doesn't exist in the natural world.
AFAIK, nobody makes anything with "300 dB of isolation".
Any engineers out there who would care to comment?

David Johnson

Scott wrote:

I missed the original post, so...
me too...

[...]

On experimental planes, we don't realy need better than RG58.
Who need more than 2m/6ft long cable?
If you see the difference beetwen the best cable and a RG58, on 6ft long you
can't realy get a real better signal on the air with a better cable.

By
--
minicab F-PRAZ
Philippe Vessaire Ò¿Ó¬

Scott wrote:
: RG-142 is nice cable, but it's not quite as flexible as RG58. The loss
: in 10 or 20 feet of RG58 isn't really worth the extra cost in my opinion...

... and at least the stuff I tried in my PA-28 had a copper-clad steel center
conductor. It screwed the compass when run up the support between the two halves of
the windscreen. I had to re-swap it back to RG-58 (MIL-C-17).

Stupid compass....

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

I worked with an X-band extreme-accuracy Atlas guidance radar at
Vandenberg AFB. It was necessary to have at least 150dB isolation to
prevent interference in our test simulator. Solid jacket cable was the
only thing that would allow this kind of performance. The Andrew cable
was also the only kind that did not generate noise when flexed or
vibrated, which was very important in our test operations. Remember
that the transponder puts out 100W-400W peak. Leaking cables in close
proximity can cross couple. Cable leakage also effects the apparent
radiation pattern of antennas, generating undesired sidelobes and
cancellations. Consider the 20' long com run from the instrument panel
to the antenna buried in the tip sail of the VariEZ or LongEZ that
passes near the extreme RFI generated by the engine's ignition. Has
anyone ever had spark noise in their com radio?

DME and the transponder are in the 960MHz to 1215MHz range. At 1GHz,
RG58 has 17.5dB/100ft., RG142 has 13.0dB/100ft., and FSJ1-50A has
6.0dB/100ft. If I was operating under extreme conditions, I would want
the best performing equipment available to me. Sometimes 1dB can make
the difference between getting a signal or not! Ask the guys talking to
the spacecraft out among the planets.