Why it’s so important to choose an
approved coaxial cable
Let’s bust a couple of myths!
Choosing RG coaxial is a mark of quality –
right?
Wrong – “RG” has become a generic term
for coaxial cable. It often relates only to a
very basic description of the physical
dimensions with little or no reference to the
electrical performance.
Do I really need MIL-DTL-17 coax?
Surely MIL-DTL-17 cables are RG
cables – what’s the difference?
• True that many of the MIL-DTL-17 specs are often referred to as RG but they are much more than that – electrical properties like maximum attenuation at a range of frequencies and physical properties like the thickness of the conductor plating are clearly defined
It’s not a true comparison
Not all coaxial cables are
created equal…..
• When Harbour Industries, a QPL
manufacturer carried out an evaluation
study some startling differences emerged
including:
– Silver plating thickness variation
– Alternative dielectric materials used
Why does the thickness of the
silver matter?
• According to the MIL-DTL specification the silver
plating should be a minimum of 40 microinches
thick – samples were measured at 29
microinches which would typically be done for
cost cutting purposes. This would leave the wire
more susceptible to corrosion.
Is PTFE really required as a
dielectric?
• Again, according to MIL-DTL-17 the required
dielectric is PTFE – in the study samples were
found with both FEP and PFA dielectrics.
• FEP has a lower performing temperature and an
inferior dissipation factor when compared to
PTFE. PFA, whilst having the same temperature
performance as PTFE shows similar dissipation
characteristics to FEP
MIL-DTL-17 QPL guarantees…
• Cables are manufactured using only qualified,
high quality materials.
• Products conform to all test requirements
through a series of rigorous QC tests.
• There is an annual government review of test
data to ensure continued compliance.
My current manufacturer is ISO
approved – isn’t that good
enough?
• Possibly so but will they guarantee the
performance laid down in MIL-DTL-17 and
supply supporting test documentation and
ask yourself why they haven’t sought QPL
approval
How do I know which coax
cable to choose?
• Check out the coaxial datasheets on our
website for full physical and electrical data
on QPL MIL-DTL-17 cables.
• In the event that a QPL cable is not
suitable we also have details on lower loss
and high strength alternatives
Conclusions
• Choosing a QPL product will guarantee
you get what you order.
• If you need alternative products to MIL-
DTL17 select a manufacturer with a QPL
pedigree such as Harbour Industries.
• Ask your manufacturer to provide test
reports to verify the cables performance.
Don’t end up with a lemon!
Beware of counterfeit products – make sure the jacket marking shows the full Mil-Spec part number, cage code and manufacturer eg:
M17/60-RG142 MIL-DTL-17 27478 Harbour Industries
How can we help you further?
• For further information on our coaxial
cables download the electrical and
dimensional data from our website.
• Alternatively call us +44 (0)1202 890975
• Or email [email protected]
Tel: +44 (0)1202 890975