PL259 Thread standard

[HRBE]

Hello to all,
I have just bought a Ground plane adaptor off Ebay (yeah I know!) (China!
Yeah I know!) it was advertised as a PL259/SO239 male/female thread to
enable a groundplane to be fitted to a mobile antenna.

I assumed wrongly that there was an International standard with regard to
the PL259/SO239.

Naturally when a known part number is advertised, one would expect that the
normal 5/8" x 24 threads per inch standard (UNEF) would be followed.

Not so! What was sent was a 16 x 1mm adaptor.

Naturally the language difference is making it hard for me to convince the
seller that he MUST advertise the adaptor on Ebay having a metric thread.

Can anyone tell me if there is a move towards the metrification of the
PL259/SO239 connectors?

If this happens all hell will break loose, imagine trying to connect antenna
to coax at say a field day or even worse in an emergency situation?

John
VK2KCE

[l***@yahoo.com]

John,
The only change in 'standards' is with truth in advertising. Not
thread size.
- 'Doc

[Ralph Mowery]

Post by HRBE
Hello to all,
I have just bought a Ground plane adaptor off Ebay (yeah I know!) (China!
Yeah I know!) it was advertised as a PL259/SO239 male/female thread to
enable a groundplane to be fitted to a mobile antenna.
I assumed wrongly that there was an International standard with regard to
the PL259/SO239.
Naturally when a known part number is advertised, one would expect that
the normal 5/8" x 24 threads per inch standard (UNEF) would be followed.
Not so! What was sent was a 16 x 1mm adaptor.
Naturally the language difference is making it hard for me to convince the
seller that he MUST advertise the adaptor on Ebay having a metric thread.
Can anyone tell me if there is a move towards the metrification of the
PL259/SO239 connectors?
If this happens all hell will break loose, imagine trying to connect
antenna to coax at say a field day or even worse in an emergency
situation?
John
VK2KCE

I am thinking MFJ put out some antenna tuners a few years back that had some
oddball so239 connectors. The threads almost matched up and youcould force
them to mate, but it was not smooth. Also think they would send you some
replacements for the so239s.

[Jeff]

Metric PL259's are quite common on some Japanese white stick antennas.
'Normal' Pl259's will not screw up tightly. I think that they are normally
known as PL259(M) although I think that there is another designation as
well.

73
Jeff

[ml]

Post by Jeff
Metric PL259's are quite common on some Japanese white stick antennas.
'Normal' Pl259's will not screw up tightly. I think that they are normally
known as PL259(M) although I think that there is another designation as
well.
73
Jeff

so i wonder why the heck would they bother comming out with a
different sized thread?

[Owen Duffy]

Post by HRBE
Hello to all,
I have just bought a Ground plane adaptor off Ebay (yeah I know!)
(China! Yeah I know!) it was advertised as a PL259/SO239 male/female
thread to enable a groundplane to be fitted to a mobile antenna.
I assumed wrongly that there was an International standard with regard
to the PL259/SO239.
Naturally when a known part number is advertised, one would expect
that the normal 5/8" x 24 threads per inch standard (UNEF) would be
followed.
Not so! What was sent was a 16 x 1mm adaptor.
Naturally the language difference is making it hard for me to convince
the seller that he MUST advertise the adaptor on Ebay having a metric
thread.
Can anyone tell me if there is a move towards the metrification of the
PL259/SO239 connectors?
If this happens all hell will break loose, imagine trying to connect
antenna to coax at say a field day or even worse in an emergency
situation?
John
VK2KCE

John,

I see you have asked this question in several places. I have read some
for what they are worth.

The Japanese manufacturers seems to have gotten a mind about a JIS for an
'equivalent' connector. I don't know this for sure, but I have come
across some incompatible look alike connectors on some well known
Japanese brand high power amplifiers.

Your Chinese parts may have been copied from one of these incompatible
connectors.

Owen

[Jeff]

Post by Owen Duffy
I see you have asked this question in several places. I have read some
for what they are worth.
The Japanese manufacturers seems to have gotten a mind about a JIS for an
'equivalent' connector. I don't know this for sure, but I have come
across some incompatible look alike connectors on some well known
Japanese brand high power amplifiers.
Your Chinese parts may have been copied from one of these incompatible
connectors.
Owen

The problem of metric PL259's is well known in the UK at least , and
adaptors and 'metric' connectors are available from Ham Radio dealers.

73
Jeff

[JIMMIE]

Post by Jeff

Post by Owen Duffy
I see you have asked this question in several places. I have read some
for what they are worth.
The Japanese manufacturers seems to have gotten a mind about a JIS for an
'equivalent' connector. I don't know this for sure, but I have come
across some incompatible look alike connectors on some well known
Japanese brand high power amplifiers.
Your Chinese parts may have been copied from one of these incompatible
connectors.
Owen

The problem of metric PL259's is well known in the UK at least , and
adaptors and 'metric' connectors are available from Ham Radio dealers.
73
Jeff

That may explain the problem I had with a couple of connectors . I was
able to borrow a die to run over them. The metric threads must be very
close to the SAE. After rethreading them they worked but I didnt like
the way the threads looked so i trashed them.

Jimmie

[Jeff]

Post by Jeff
The problem of metric PL259's is well known in the UK at least , and
adaptors and 'metric' connectors are available from Ham Radio dealers.
73
Jeff
That may explain the problem I had with a couple of connectors . I was

able to borrow a die to run over them. The metric threads must be very
close to the SAE. After rethreading them they worked but I didnt like
the way the threads looked so i trashed them.


Yes, they normally do up most of the way and then bind just before the inner
part has mated with the serrated teeth, so it is easy to miss if you don't
check that the cable is not free to rotate.

73
Jeff

[Dan Yemiola AI8O]

Post by HRBE
I assumed wrongly that there was an International standard with regard to
the PL259/SO239.
Naturally when a known part number is advertised, one would expect that
the normal 5/8" x 24 threads per inch standard (UNEF) would be followed.

The original PL-259 was a World War 2 US military JANAP standard.
It had specifications for all the critical fit parts of a PL-259 connector.
Eventually the JANAP standard morphed into a US Mil-Spec Standard.
The current standard hasn't changed much since WW2.
A metric thread does not meet the standard.
If somebody says its a PL-259; they should meet that standard or say it is
similar but NOT compatible.
Too many manufacturers have gotten sloppy in their QC.

[Dan Richardson]

Post by HRBE
Hello to all,
I have just bought a Ground plane adaptor off Ebay (yeah I know!) (China!
Yeah I know!) it was advertised as a PL259/SO239 male/female thread to
enable a groundplane to be fitted to a mobile antenna.
I assumed wrongly that there was an International standard with regard to
the PL259/SO239.
Naturally when a known part number is advertised, one would expect that the
normal 5/8" x 24 threads per inch standard (UNEF) would be followed.
Not so! What was sent was a 16 x 1mm adaptor.
Naturally the language difference is making it hard for me to convince the
seller that he MUST advertise the adaptor on Ebay having a metric thread.
Can anyone tell me if there is a move towards the metrification of the
PL259/SO239 connectors?
If this happens all hell will break loose, imagine trying to connect antenna
to coax at say a field day or even worse in an emergency situation?
John
VK2KCE

I ran into that problem many years ago when they first starting
importing some off-shore VHF antennas. I ended up purchasing a 5/8-24
NF die-nut and that took care of the problem. Its very easy to use
requiring very little pressure to "chase" the threads so that a
standard PL-259 screws on without any problem.

Over the years having that die-nut has paid for itself many times for
myself and friends who ended up trying to use metric connectors with
American standard connectors.

Danny, K6MHE

[John VK2KCE]

Thanks Dan,
I have ordered a die nut to correct the problem, I suspect that the thread
will not have the full strength after using it though!

Thanks, John

Post by Dan Richardson

Post by HRBE
Hello to all,
I have just bought a Ground plane adaptor off Ebay (yeah I know!) (China!
Yeah I know!) it was advertised as a PL259/SO239 male/female thread to
enable a groundplane to be fitted to a mobile antenna.
I assumed wrongly that there was an International standard with regard to
the PL259/SO239.
Naturally when a known part number is advertised, one would expect that the
normal 5/8" x 24 threads per inch standard (UNEF) would be followed.
Not so! What was sent was a 16 x 1mm adaptor.
Naturally the language difference is making it hard for me to convince the
seller that he MUST advertise the adaptor on Ebay having a metric thread.
Can anyone tell me if there is a move towards the metrification of the
PL259/SO239 connectors?
If this happens all hell will break loose, imagine trying to connect antenna
to coax at say a field day or even worse in an emergency situation?
John
VK2KCE

I ran into that problem many years ago when they first starting
importing some off-shore VHF antennas. I ended up purchasing a 5/8-24
NF die-nut and that took care of the problem. Its very easy to use
requiring very little pressure to "chase" the threads so that a
standard PL-259 screws on without any problem.
Over the years having that die-nut has paid for itself many times for
myself and friends who ended up trying to use metric connectors with
American standard connectors.
Danny, K6MHE

[Jeff]

Post by John VK2KCE
Thanks Dan,
I have ordered a die nut to correct the problem, I suspect that the thread
will not have the full strength after using it though!

Whist running a die over the thread will allow a 'normal' 259 the be screwed
onto the socket it does reduce some of the thread to almost nothing, so I
would not recommend that method where there is any mechanical strength
required such as an antenna base.

73
Jeff

[Dan Richardson]

Post by Jeff

Post by John VK2KCE
Thanks Dan,
I have ordered a die nut to correct the problem, I suspect that the thread
will not have the full strength after using it though!

Whist running a die over the thread will allow a 'normal' 259 the be screwed
onto the socket it does reduce some of the thread to almost nothing, so I
would not recommend that method where there is any mechanical strength
required such as an antenna base.
73
Jeff

In over 20+ years of use I have never experienced anything like that.
If you think about it, the difference between the metric and american
threads - in the case is - is slight (Look just how far you can screw
a PL-59 on the meteric socket) and a very small amout of material is
removed.

Have you really ever tried this method?

73,
Danny, K6MHE

[Jeff]

Post by Dan Richardson

Post by Jeff
Whist running a die over the thread will allow a 'normal' 259 the be screwed
onto the socket it does reduce some of the thread to almost nothing, so I
would not recommend that method where there is any mechanical strength
required such as an antenna base.
73
Jeff

In over 20+ years of use I have never experienced anything like that.
If you think about it, the difference between the metric and american
threads - in the case is - is slight (Look just how far you can screw
a PL-59 on the meteric socket) and a very small amout of material is
removed.

What you will see if you actually try this method is that the threads will
be reduced in thickness over about half the length. The reduction getting
worse as you progress. The threads will have reduced to such an extent
towards the end as to render then no more than bumps. Have a look at one you
have done this to under a magnifying glass and you will see.

73
Jeff

[unknown]

Post by Jeff

Post by Dan Richardson

Post by Jeff
Whist running a die over the thread will allow a 'normal' 259 the be screwed
onto the socket it does reduce some of the thread to almost nothing, so I
would not recommend that method where there is any mechanical strength
required such as an antenna base.
73
Jeff

In over 20+ years of use I have never experienced anything like that.
If you think about it, the difference between the metric and american
threads - in the case is - is slight (Look just how far you can screw
a PL-59 on the meteric socket) and a very small amout of material is
removed.

What you will see if you actually try this method is that the threads will
be reduced in thickness over about half the length. The reduction getting
worse as you progress. The threads will have reduced to such an extent
towards the end as to render then no more than bumps. Have a look at one you
have done this to under a magnifying glass and you will see.
73
Jeff

Jeff,

The TPI between the two standards (American and metric) - in this
case - are very close resulting in very little thread stock being
removed. In the short thread length involved here (about 1/2-inch) and
the threads are not rendered to nothing more than bumps.However, at
longer thread lengths it well could be a problem, but not at the
1/2-inch distance we are talking about here.

Again I ask, have you actually tried this?

I have used this method numerous times for myself and friends and I
have never experienced any kind of failures or problems in doing so.

That said I'm going QRT on this subject.

73,
Danny, K6MHE

[Jeff]

Post by unknown
The TPI between the two standards (American and metric) - in this
case - are very close resulting in very little thread stock being
removed. In the short thread length involved here (about 1/2-inch) and
the threads are not rendered to nothing more than bumps.However, at
longer thread lengths it well could be a problem, but not at the
1/2-inch distance we are talking about here.
Again I ask, have you actually tried this?
I have used this method numerous times for myself and friends and I
have never experienced any kind of failures or problems in doing so.

Yes. and I would not trust the end result to any kind of load, it is fine
for a cable connection but certainly not as a method of retaining a mobile
antenna at speed!

Perhaps the difference is in the die, and the length of thread in the die.
The thicker the die the truer the thread will be and the more pronounced the
removal of the metric thread.

The OP was suggesting a 'die nut' which will be quite thick and I suspect
would produce results similar to those I have found.

Jeff

[Jeff]

Post by unknown
The TPI between the two standards (American and metric) - in this
case - are very close resulting in very little thread stock being
removed.

In fact the TPI's are not that close 24tpi for American (1.06mm pitch) and
1.5mm pitch for Metric fine.

Jeff

[Gene Fuller]

Post by Jeff

Post by unknown
The TPI between the two standards (American and metric) - in this
case - are very close resulting in very little thread stock being
removed.

In fact the TPI's are not that close 24tpi for American (1.06mm pitch) and
1.5mm pitch for Metric fine.
Jeff

The metric PL259 has a pitch of 1.0 mm. It is not an ordinary metric
fine thread. (5/8 - 24 is not an ordinary fine thread either.)

73,
Gene
W4SZ

[Dan Richardson]

Post by John VK2KCE
Thanks Dan,
I have ordered a die nut to correct the problem, I suspect that the thread
will not have the full strength after using it though!

Once you try this method you see that you really have nothing to be
concerned about. (Unless you use a wrench and really apply heavy
pressure on a PL-259.) For hand tightening you'll have no problems.

73, Danny.