As a "personal choice", my hands are no longer steady enough to prevent
getting solder on the outside of the center pin so I'm relegated to
using the crimp type although I'd not seen any for the DIN. I would add
that I can now hold the solder with my left hand if a lot of movement
isn't required.
I "would think" if the commercial guys are using crimp, it should be
reliable enough.
OTOH I think this is a good place for long time users to chime in with
their experiences.
73
Roger (K8RI)
On 9/5/2016 Monday 8:44 PM, Bob K6UJ wrote:
Roger,
Great overview on connectors !
One thing that I am wondering about is whether or not to get the
solder type
center pin on the DIN connectors. I see them clamp or crimp style for
the outer shield and also
solder or non solder on the center pin. I like the crimp style outer
and clamp is fine too, but not sure
if getting a non solder center pin is a concern. Whats your view on
the center pin attachment ?
I remember discussions here on Tower Talk in the past about center pin
creep in type N connectors.
The DIN is a different animal though...........
Bob
K6UJ
On 9/5/16 5:08 PM, Roger (K8RI) on TT wrote:
I see a lot of preferences from UHF, To :N: type, to DIN, but for the
average ham, does it make a difference?
Take UHF, essentially the design is crude and they are cheap! The
loss figures are high, but those figures are for frequencies few hams
ever approach and the connector specs say up to 300 MHz and 500
volts.. On HF the loss is minuscule. The arguments are those figures
add up and they do, but it's still a very small value. With SO2R and
remote antenna switches, plus the rotator loops and pigtails to the
antennas I've counted as many as ten connectors between the rig and
antennas, but the loss was barely detectable. Impedance bumps? Yes,
they are there, but what do the mean? Added up for the 160 through 10
meter bands, they are insignificant. I can see where the reflections
"might" make a difference with digital modes, but it's still very
small. The only down side I can see is the learning curve for the
solder types. "Probably" the average ham does a miserable job of
soldering them, over heating the connector and coax when soldering
the braid, turning the coax dielectric into a mass of goo, while
getting solder on the exterior of the center conductor pin.
Off brand UHF connectors: Many adherents say Amphenol
http://www.amphenolrf.com/connectors/uhf.html is the only way to go
and they do have reasonably good quality control. As I said at the
beginning, the original connector design is crude, but it was
designed long ago. They are easy to make, so there are many off
brand connectors of various qualities. Amphenol lists both Nickel and
silver finish as well as a whole slew of dielectrics from Phenolic
and Styrene, to Teflon and more. The off brand stuff varies, but a
good inspection by the Ham who knows what to look for, there are good
ones out there. The typical Ham would do better sticking with known
brands, but with the UHF design, the important point is whether the
particular connector will pass the test of time. OTOH even
top-of-the-line connectors are inexpensive and if you purchase very
many, the discount makes them about the price of the stuff you see at
the swaps..
Installed according to the directions (braid on the inside and
properly soldered), the connector will provide reasonable
strength. NOTE UHF connectors are not weatherproof!
N-Type. Not for those running "high power". By high power, I'm nor
referring to 1500 watts.
http://www.amphenolrf.com/connectors/n-type.html OK, so they
represent less insertion loss with less impedance, but what do they
gain us at 160 through 10?. Amphenol lists them "These connectors
are used in all systems where excellent RF and mechanical performance
is critical." I'm not sure by what they mean when they refer to
mechanical performance, but I've never found the typical N-type
connector I couldn't pull off the coax with my hands (crimp type
excepted) In my experience, They have two limitations. Mechanical
strength and center pin migration are the problems I've seen.
Mechanical strength is pretty much self explanatory. Center Pin
Migration? On vertical runs, the center conductor in many, if not
most coax cables will slowly move downward This tends to pull the
center pin, in on the top connector, and push the center pin out on
the bottom connector. This doesn't happen with connectors where the
center pin is captive.
DIN (7-16) connectors.
https://en.wikipedia.org/wiki/7/16_DIN_connector Is kinda like an
N-connectors on steroids. The 7-16, or 7/16 is the size of the center
pin (7 mm) and the ID of the outer connector (16 mm) They are still a
bit on the expensive side and not for the ham who purchases
connectors at swaps to save a buck, but " It is among the most widely
used high power RF connectors in cellular network
<https://en.wikipedia.org/wiki/Cellular_network> antenna systems."
and "The 7-16 DIN connector out performs other non-flange options,
such as N connectors <https://en.wikipedia.org/wiki/N_connector> or
BNC connectors <https://en.wikipedia.org/wiki/BNC_connector>, when it
comes to interference and intermodulation rejection or higher power
handling at RF frequencies.^[1]
<https://en.wikipedia.org/wiki/7/16_DIN_connector#cite_note-UTC-1>"
(Quoted from the above Link)
Adapters: Amphenol lists 689 adapters. Pages from
http://www.amphenolrf.com/adapters.html However, other than the most
common it's likely the distributor would need to special order them.
Crimp, Vs solder. Other than requiring a specialized crimp tool,
crimp connectors tend to be more uniform, faster to install, and
mechanically stronger than the solder type. Properly adjusted cable
prep tools (strippers) really speed things up and present identical
cable ends to the connectors with the proper dimensions. Nearly
identical crimp tools can be found with widely varying prices. One
crimp tool with two sets of inserts can cover cables from RG-58
through RG-8 (LMR-400) sizes. Depending on the vendor, nearly all
connectors for these cables are available in solder or crimp versions.
NOTE The RG designation has not been a specification for many years.
It simply refers to cable sizes. Nothing more.
So the question is, why would the average, or typical ham need
anything other than the crimp, or solder, UHF connector?
A SIDE NOTE: on weather proofing: There are several approaches to
weatherproofing. One uses vinyl electrical tape wound sticky side out
over the connectors, to keep the weatherproofing material (coax seal,
various self vulcanizing tapes, and "flooded" heat shrink tubing)
from sticking to the connector Flooded heat shrink tubing has a layer
of hot melt glue on the inside. If you don't want the glue to stick
to the connector, a film of Silicone grease or mold release agent,
will allow for a seal without the glue sticking to the connector.
Just don't get any on the coax jacket. Me? I make sure it's all
clean and bond to the whole works.
By bonding to the coax jackets and the connectors, the flooded heat
shrink tubing makes for a very strong mechanical connection.
One other comment: In over 55 years as a ham, I've only seen two bad
connectors from Amphenol. I can't say that for the few "brand
unknown", I've purchased from swaps.
73
Roger (K8RI)
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Roger (K8RI)
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