What about http://www.partsconnexion.com/catalog/connectors_files/sheet006.html
They have gold plated BNCs, although there is no mention of the impedance. I think these are for audio applications, so hopefully they are 75 ohms.
Hope this helps,
Stu
They have gold plated BNCs, although there is no mention of the impedance. I think these are for audio applications, so hopefully they are 75 ohms.
Hope this helps,
Stu
Most BNCs have gold-plated center pin.
The vast majority of BNCs are 50 Ohm characteristic impedance.
Very few BNCs are 75 Ohm and the design of these makes them
less rugged. (it's very common to have 50 Ohm BNCs that
mate to 75 Ohm coaxes)
I doubt that for even digital audio interconnections the
difference in connection impedance will be noticable in
either objective or "subjective" terms.
The vast majority of BNCs are 50 Ohm characteristic impedance.
Very few BNCs are 75 Ohm and the design of these makes them
less rugged. (it's very common to have 50 Ohm BNCs that
mate to 75 Ohm coaxes)
I doubt that for even digital audio interconnections the
difference in connection impedance will be noticable in
either objective or "subjective" terms.
maczrool said:What about http://www.partsconnexion.com/catalog/connectors_files/sheet006.html
They have gold plated BNCs, although there is no mention of the impedance. I think these are for audio applications, so hopefully they are 75 ohms.
----------------------------------------
Not listed under url or in catalog; where did you pick this up from pl?
fmak,
There is no reason to assume that since a BNC is
supposedly for "audio applications", that it is 75 Ohms.
As I said VERY FEW BNCs ARE 75 OHM. They are VERY HARD
TO FIND and not much used except for serious RF work
where 75 Ohm characteristic impedance is important.
To the contrary, any BNC from an audiophile part source,
is likely to be 50 Ohms, with 99.99% probability.
There is no reason to assume that since a BNC is
supposedly for "audio applications", that it is 75 Ohms.
As I said VERY FEW BNCs ARE 75 OHM. They are VERY HARD
TO FIND and not much used except for serious RF work
where 75 Ohm characteristic impedance is important.
To the contrary, any BNC from an audiophile part source,
is likely to be 50 Ohms, with 99.99% probability.
Oh boy.......!
Time to make more enemies............
In a good SPDIF interface, you can hear (and measure!) the effects of 75 ohm vs. 50 ohm BNCs.
75 ohm BNCs have the center teflon removed to lower the capacitance. And are compatible with 50 ohm ones.
75 ohm TNCs have a smaller center pin, and are not compatible with the 50 ohm types.
To assume that it is 75 ohm because it is supposedly for audio is really funny. These guys will also sell you a "75 ohm RCA", because some clown claims to make one.
Too bad it isn't..............
Jocko
Time to make more enemies............
In a good SPDIF interface, you can hear (and measure!) the effects of 75 ohm vs. 50 ohm BNCs.
75 ohm BNCs have the center teflon removed to lower the capacitance. And are compatible with 50 ohm ones.
75 ohm TNCs have a smaller center pin, and are not compatible with the 50 ohm types.
To assume that it is 75 ohm because it is supposedly for audio is really funny. These guys will also sell you a "75 ohm RCA", because some clown claims to make one.
Too bad it isn't..............
Jocko
Well, maybe not totally clueless.........
But certainly TDR-less.
Speaking of which.......since I need money.........
Anyone who thinks that they really have a "75 ohm RCA", here is what you do:
Send me $500, along with a date, time, and place to appear. Along with a phone number, as I will surely get lost.
You bring your magic connector.
I bring my TDR, some 50 & 75 ohm cables, and connector/adaptors, etc. I'll even bring a D/A box so that you can hear the different effects all this stuff has.
Then after you apologize for being reading Stereophile for much too long, we can go get pizza.
I might even buy.
(This offer only good if there is a land route from Texas. Foreign prices available upon request.)
Jocko
But certainly TDR-less.
Speaking of which.......since I need money.........
Anyone who thinks that they really have a "75 ohm RCA", here is what you do:
Send me $500, along with a date, time, and place to appear. Along with a phone number, as I will surely get lost.
You bring your magic connector.
I bring my TDR, some 50 & 75 ohm cables, and connector/adaptors, etc. I'll even bring a D/A box so that you can hear the different effects all this stuff has.
Then after you apologize for being reading Stereophile for much too long, we can go get pizza.
I might even buy.
(This offer only good if there is a land route from Texas. Foreign prices available upon request.)
Jocko
Jocko,
You haven't made any more enemies ... yet ... ;-)
I can believe that you'd notice the difference between
50 Ohm and 75 Ohm SPDIF BNCs on a TDR given that everything
else is "up to spec". I would think it hard to notice on a
digital audio connection unless EVERYTHING were perfect --
BNCs on the two boxes connected straight to circuit boards,
proper transmission line impedances on the boards, etc.
But how many setups, aside from yours, would be so well
done? I'd think that the couple inches of twisted pair wire
between the chassis-mounted BNC and the circuit board in
most setups would swamp any effects of the 50- vs 75-Ohm
connectors.
(why not just make it easier on one's self and do it all in
50-Ohm impedances? Oh, yeah, there's "the spec")
If you take the I-10 land route west from your home to mine,
I'll sell you some local swamp land to go with your 75-Ohm
RCAs. (hey, if they really wanted controlled impedances, they'd
have used Motorola connectors, right? ;-) )
You haven't made any more enemies ... yet ... ;-)
I can believe that you'd notice the difference between
50 Ohm and 75 Ohm SPDIF BNCs on a TDR given that everything
else is "up to spec". I would think it hard to notice on a
digital audio connection unless EVERYTHING were perfect --
BNCs on the two boxes connected straight to circuit boards,
proper transmission line impedances on the boards, etc.
But how many setups, aside from yours, would be so well
done? I'd think that the couple inches of twisted pair wire
between the chassis-mounted BNC and the circuit board in
most setups would swamp any effects of the 50- vs 75-Ohm
connectors.
(why not just make it easier on one's self and do it all in
50-Ohm impedances? Oh, yeah, there's "the spec")
If you take the I-10 land route west from your home to mine,
I'll sell you some local swamp land to go with your 75-Ohm
RCAs. (hey, if they really wanted controlled impedances, they'd
have used Motorola connectors, right? ;-) )
Twisted pair!!!!!!!!!!!!!!!!!!!
No way, Jose.
A customer in Chicago did that once. Then he sent back his D/A box because it sounded like crap. That, and he somehow ruined the mute relay in the process.
Hey, it made great interconnect cable; he could not grasp why it didn't work for SPDIF.
On my setup, I can see, measure, and hear the effect of breaking the center conductor out from the shield. I thought about using bulkhead feedthrough BNCs, but they were almost $20 each. Instead, I found a cheaper way to "swamp" the effects.
With customers like the guy in Chicago, it is pointless to spend that kind of money on them. Because they always know how to improve everything.
But on my personal unit...............
Hey.....we could use GR connectors! Or APC-7. Or APC-3.5.........and Gore-Tex.
Jocko
No way, Jose.
A customer in Chicago did that once. Then he sent back his D/A box because it sounded like crap. That, and he somehow ruined the mute relay in the process.
Hey, it made great interconnect cable; he could not grasp why it didn't work for SPDIF.
On my setup, I can see, measure, and hear the effect of breaking the center conductor out from the shield. I thought about using bulkhead feedthrough BNCs, but they were almost $20 each. Instead, I found a cheaper way to "swamp" the effects.
With customers like the guy in Chicago, it is pointless to spend that kind of money on them. Because they always know how to improve everything.
But on my personal unit...............
Hey.....we could use GR connectors! Or APC-7. Or APC-3.5.........and Gore-Tex.
Jocko
Jocko,
Do you mean "GR connector" as in that really old
hermaphroditic coax connector, or do you mean the
dual banana plug? (don't try to convince me that THIS is 75 OHM!)
Yes, APC7 would be great. Something worthy of audio!
Hard line coax with teflon dielectric...
To swerve slightly, what would you recommend for the
"ideal" way to take digits from a bit reader to a DAC box?
I don't really like the idea of "separates", but I fear that all
the work that one can spend tweaking a one-box unit
will be wasted when the transport or laser dies.
Do you mean "GR connector" as in that really old
hermaphroditic coax connector, or do you mean the
dual banana plug? (don't try to convince me that THIS is 75 OHM!)
Yes, APC7 would be great. Something worthy of audio!
Hard line coax with teflon dielectric...
To swerve slightly, what would you recommend for the
"ideal" way to take digits from a bit reader to a DAC box?
I don't really like the idea of "separates", but I fear that all
the work that one can spend tweaking a one-box unit
will be wasted when the transport or laser dies.
Jocko's onto something
I can't think of anything more appropriate to satisfying the needs of connector jewellery / hauser-sized umbilical cables than some APC-7 and some heliax or similar
For those of a more delicate disposition you could offer SMA and semi-rigid
If you can get them in 75R that is...
Andy.
I can't think of anything more appropriate to satisfying the needs of connector jewellery / hauser-sized umbilical cables than some APC-7 and some heliax or similar
For those of a more delicate disposition you could offer SMA and semi-rigid
If you can get them in 75R that is...
Andy.
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