hi

I was wanting to dispel some myths about connector losses

lets assume my worst case freq 450mhz LOW /week singal work

lets assume my worst coax is ether lmr400 or 600 (not imp )

so naturally i'd use typically N connectors

how much do i lose if I screw in a right angle adapter?

in general at the base of a radio

and same question say i want to join to lengths of coax and use a
small stubby f/f N connector adapter ??


lose going from a DIN to an N via a adapter?? at radio and 'inline'

joining 2 coax lengths


some say the loss is actually neg some say it's going to add up and
the insertion loss could easily go over 1/2 db i dunno


exactly how good/bad is it?



and where can u get some good low loss adapters (i know of ampenol) I
bought some unknowns at a flea market and they had great loss to which
in that case i attribute to just poor quality


thanks to all those in advance that help me put the hamster back on the
wheel

ml

"ml" wrote in message
...
hi

I was wanting to dispel some myths about connector losses

lets assume my worst case freq 450mhz LOW /week singal work

lets assume my worst coax is ether lmr400 or 600 (not imp )

so naturally i'd use typically N connectors

how much do i lose if I screw in a right angle adapter?


My comment would be on the right angle N connectors. They vary dramatically.
My area of interest is 1296MHz EME where any loss before the Feedhorn LNA
shows up easily. I have an HP network analyzer and qualified a number of
right angle N's. In general the adapter with a square block at the elbow
were fine- under -0.03 dB. The gradual bend (called a sweep in plumbing
terms I believe) had unacceptable return loss and much higher loss (sorry,
no figures there).

Dale W4OP

On Sat, 30 Sep 2006 13:31:09 GMT, ml wrote:

hi

I was wanting to dispel some myths about connector losses

Hi Myles,

They are largely myths. The true fact of the matter is in quality of
construction and selection of materials. However, even there with a
dedicated connection that is wrapped against the environment, a cheap
materials connector will work as well (still, it must have good
construction).

lose going from a DIN to an N via a adapter??

That's a new one on me. There are a lot of DIN standards.

some say the loss is actually neg some say it's going to add up and
the insertion loss could easily go over 1/2 db i dunno

Negatives add up to bigger negatives. The point of negatives is in
application. You can say a connector is specified at -0.1dB or that
it has 0.1dB loss - same thing. To say it has -0.1dB loss is
something of an anachronism, but it is often encountered.

exactly how good/bad is it?

Same dependencies I've already mentioned. You probably couldn't
measure it without sophisticated tools.

and where can u get some good low loss adapters (i know of ampenol) I
bought some unknowns at a flea market and they had great loss to which
in that case i attribute to just poor quality

I would then have to ask: How do you know they had "great loss?" 1dB
loss at the connection point would be as hot as a Christmas tree
lightbulb for 100W passing through it.

73's
Richard Clark, KB7QHC

In article t3vTg.1268$753.976@trnddc05,
"Dale Parfitt" wrote:

"ml" wrote in message
...
hi

I was wanting to dispel some myths about connector losses

lets assume my worst case freq 450mhz LOW /week singal work

lets assume my worst coax is ether lmr400 or 600 (not imp )

so naturally i'd use typically N connectors

how much do i lose if I screw in a right angle adapter?


My comment would be on the right angle N connectors. They vary dramatically.
My area of interest is 1296MHz EME where any loss before the Feedhorn LNA
shows up easily. I have an HP network analyzer and qualified a number of
right angle N's. In general the adapter with a square block at the elbow
were fine- under -0.03 dB. The gradual bend (called a sweep in plumbing
terms I believe) had unacceptable return loss and much higher loss (sorry,
no figures there).

Dale W4OP

thanks rich and dale

appreciate the help!

rich i new the connector was bad cause i noticed less power on my meter
swapped it out, got a few lemons

dale: wow i always wondered about those elebow square designs ,
not sure what you ment by the 'gradual' bend ones i've seen the
'standard' right angle connectors but werent' 'gentle' they were 90
hard bends is this what you ment?


or did you ment if you simply made a gentle arc in the coax vs using
a rt angle connector tht a good connector rt angle adapter was better


i'd like to put a few adapters both F/F and rt angles on but didn't
want to do it if it would kill me loss wise


thanks

"ml" wrote in message
...
In article t3vTg.1268$753.976@trnddc05,
"Dale Parfitt" wrote:

"ml" wrote in message
...
hi

I was wanting to dispel some myths about connector losses

lets assume my worst case freq 450mhz LOW /week singal work

lets assume my worst coax is ether lmr400 or 600 (not imp )

so naturally i'd use typically N connectors

how much do i lose if I screw in a right angle adapter?


My comment would be on the right angle N connectors. They vary
dramatically.
My area of interest is 1296MHz EME where any loss before the Feedhorn LNA
shows up easily. I have an HP network analyzer and qualified a number of
right angle N's. In general the adapter with a square block at the elbow
were fine- under -0.03 dB. The gradual bend (called a sweep in plumbing
terms I believe) had unacceptable return loss and much higher loss
(sorry,
no figures there).

Dale W4OP

thanks rich and dale

appreciate the help!

rich i new the connector was bad cause i noticed less power on my meter
swapped it out, got a few lemons

dale: wow i always wondered about those elebow square designs ,
not sure what you ment by the 'gradual' bend ones i've seen the
'standard' right angle connectors but werent' 'gentle' they were 90
hard bends is this what you ment?


or did you ment if you simply made a gentle arc in the coax vs using
a rt angle connector tht a good connector rt angle adapter was better


i'd like to put a few adapters both F/F and rt angles on but didn't
want to do it if it would kill me loss wise


thanks
Both are 90 degree elbows- from my measurements the ones that have a square
block of metal at the elbow were fine. The ones that looked like a 90 degree
plumbing sweep had bad return loss. This may vary from mfg to mfg, but Al
Ward W5LUA who has had experience up through 24GHz agrees.
Perhaps I'll get time and inclination to mill one of the sweep styles open
and see what's up.
Dale W4OP

"ml" wrote in message
...
hi

I was wanting to dispel some myths about connector losses

lets assume my worst case freq 450mhz LOW /week singal work

lets assume my worst coax is ether lmr400 or 600 (not imp )

so naturally i'd use typically N connectors

how much do i lose if I screw in a right angle adapter?

in general at the base of a radio

and same question say i want to join to lengths of coax and use a
small stubby f/f N connector adapter ??


lose going from a DIN to an N via a adapter?? at radio and 'inline'

joining 2 coax lengths


some say the loss is actually neg some say it's going to add up and
the insertion loss could easily go over 1/2 db i dunno


I can help a little, just not at 450 MHz.

In the 1970's I had the TV system on an aircraft carrier for maintenance.
One slow day at sea, I tested the connector-loss stories. I took the
longest piece of RG-59 I had (about 60' or so) and measured the loss around
60 MHz, Channel 3, the freq of my test generator. Next, I joined about ten
pieces of RG-59 together to make the same length and repeated the
measurement. I was surprised at my result: only about 1 dB more loss.
Certainly nothing like the mythical 1 dB per connector figure that had been
bandied about. Plus, crimped-on F-59 connectors have nothing to recommend
them, compared to N-type connectors we use for UHF hamming. I did not
have any right-angle F-connectors to test then. I have some now and I have
modulators I can tune to UHF to source a stable signal. Maybe I'll run some
more tests.

Both are 90 degree elbows- from my measurements the ones that have a
square block of metal at the elbow were fine. The ones that looked like a
90 degree plumbing sweep had bad return loss. This may vary from mfg to
mfg, but Al Ward W5LUA who has had experience up through 24GHz agrees.
Perhaps I'll get time and inclination to mill one of the sweep styles open
and see what's up.
Dale W4OP


This is a very strange result, the non 90 degree elbow ones, normally
referred to as "swept radius" are intended to reduce the step
discontinuities that the a 90 elbow type introduce. They are usually used at
microwave frequencies where these discontinuities are more apparent.

73
Jeff

In article 3eFTg.217$pS3.30@trnddc01,
"Dale Parfitt" wrote:

"ml" wrote in message
...
In article t3vTg.1268$753.976@trnddc05,
"Dale Parfitt" wrote:

"ml" wrote in message
...
hi

I was wanting to dispel some myths about connector losses

lets assume my worst case freq 450mhz LOW /week singal work

lets assume my worst coax is ether lmr400 or 600 (not imp )

so naturally i'd use typically N connectors

how much do i lose if I screw in a right angle adapter?


My comment would be on the right angle N connectors. They vary
dramatically.
My area of interest is 1296MHz EME where any loss before the Feedhorn LNA
shows up easily. I have an HP network analyzer and qualified a number of
right angle N's. In general the adapter with a square block at the elbow
were fine- under -0.03 dB. The gradual bend (called a sweep in plumbing
terms I believe) had unacceptable return loss and much higher loss
(sorry,
no figures there).

Dale W4OP

thanks rich and dale

appreciate the help!

rich i new the connector was bad cause i noticed less power on my meter
swapped it out, got a few lemons

dale: wow i always wondered about those elebow square designs ,
not sure what you ment by the 'gradual' bend ones i've seen the
'standard' right angle connectors but werent' 'gentle' they were 90
hard bends is this what you ment?


or did you ment if you simply made a gentle arc in the coax vs using
a rt angle connector tht a good connector rt angle adapter was better


i'd like to put a few adapters both F/F and rt angles on but didn't
want to do it if it would kill me loss wise


thanks
Both are 90 degree elbows- from my measurements the ones that have a square
block of metal at the elbow were fine. The ones that looked like a 90 degree
plumbing sweep had bad return loss. This may vary from mfg to mfg, but Al
Ward W5LUA who has had experience up through 24GHz agrees.
Perhaps I'll get time and inclination to mill one of the sweep styles open
and see what's up.
Dale W4OP

that would be a very interesting experiment I guess i could hack saw
open a regular 90 elbow rt angle but i thinkk i know what i would find
and guess why they wouldn't work well could be wrong i have no test
gear.... but i couldn't open the 'square' one it's not easy to hacksaw
the one i have has a 'screw' at the square elbow but its cosmetic it
won't 'openup'

i really should find someone w/some sort of test rig and take some
N--pl259 and etc adapters as well as some 90 adapters and do a
experiment if i win the lotto i'd buy a rack of test gear (only a
ham nerd would do that)

thanks very much

In article , "Jeff"
wrote:

Both are 90 degree elbows- from my measurements the ones that have a
square block of metal at the elbow were fine. The ones that looked like a
90 degree plumbing sweep had bad return loss. This may vary from mfg to
mfg, but Al Ward W5LUA who has had experience up through 24GHz agrees.
Perhaps I'll get time and inclination to mill one of the sweep styles open
and see what's up.
Dale W4OP


This is a very strange result, the non 90 degree elbow ones, normally
referred to as "swept radius" are intended to reduce the step
discontinuities that the a 90 elbow type introduce. They are usually used at
microwave frequencies where these discontinuities are more apparent.

73
Jeff

yeah now that i had a chance to check some manuf spec's seems the
losses they post for the regular rt angles looking like 2 pipe pieces
mitered and the 'square' ones seem to have same loss .1 etc 11gig

and are less ten bucks

the swep ones i saw were rated to 18gig wow and like 150bucks loss
and swr were about the same but from the very high end atten was
best


obv i don't have any first hand exp so i am not disagreeing

i know when i've had the chance to test connectors in the past
sometimes you did get some really dissapointing results

m