BNC Chess

Nice! ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

The APC7 is an amazing connector. It is a switch hitter. ;-)

So they got the board right (white square, lower right), but is the queen on her color? I can't tell. :)

I noticed that the relative value of each piece has no correlation to the frequency limit of the connector/adapter.

Actually, no (I didn't notice until you said something). The convention is that "white" is the piece without another color. The queen should be on her own color.

Frequency limit? They're adapters. What's the limit? "White" and "black" pieces aren't the same, either. It would be a difficult game to play.

Creatively designed chess sets are the exclusive preserve of patzers.

(Not that I'm a particularly good chess player myself, of course.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net

APC-7 is a hermaphrodite connector. It's not sexy. I always wonder where my coax adapters disappear to after every Field Day. Now, I know.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Probably why I like them. But the pieces on both sides should be the same, anyway. These are a little too geeky for even me.

I'm not that good; patzer extrordinare.

Well an hermaphrodite could be a switch hitter.

I can't think of another connector that is both sexes.

See:

Has to do with TEM mode and cutoff, just like a piece of coax/waveguide. BTW, this may not be the best reference. For example, I noticed they claim BNC's are good to 4 GHz but I've never had that experience. I don't use t hem over 2 GHz. I think Pasternack has a similar chart and they recommend

2 GHz (or maybe even 1 GHz?). Of course their recommendation may consider properties other than cutoff - such as warranty returns. :)

Now, what's the capability of a random ADAPTER, say, between "N" and BNC?

From memory the 70's, a well constructed N type works out to 18GHz, HP invented APC works out to 22GHz.

BNC? ...I'll stop laughing now. Do you mean a new one or an 'old' one. do you mean mfgr style, field style, or ???

I hear you, but for field work, BNC's are pretty hard to beat for convenience. Very easy to attach/remove from equipment, analyzers, etc...

You left out the part about nickel plated vs. silver. I've used some that must have been made out of pewter! Maybe even pig iron, or left over slag from a blast furnace. :)

GR connector:

-- Jeff Liebermann snipped-for-privacy@cruzio.com

150 Felker St #D Santa Cruz CA 95060 Skype: JeffLiebermann AE6KS 831-336-2558

Exactly. Now try the adapter.

GR874

--
"Design is the reverse of analysis" 
                   (R.D. Middlebrook)

You posted ahead of me on that one :-)

I still have some 874 interseries adapters. Some of my GR capacitance standards use 874s. Older Tek calibration gear, too. I have a Tek peak-to-peak detector that's GR874 in, BNC out. Used it last week.

The 7 and 14mm coplanar connectors used on some network analyzers are genderless, too. Lucky to find any under a couple hundred bucks each.

--
"Design is the reverse of analysis" 
                   (R.D. Middlebrook)

Random capabilities, of course. I have no fear of coax adapters.

String of random capability adapters: (Sorry about the otto focus photos, but I didn't take the photos). Vertical is 1 dB per division. Losses are a little worse than the same length of small diameter coax cable. 23 random connectors, 2.1dB at 2.4GHz or about 0.09dB/connector.

The last time I did this type of test, I used a mess of BNC "T" connectors in series (that I inherited when I ripped out a large

10base2 "cheapernet" LAN). I think the chain was about 6ft long. Despite the "stub" formed by the unterminated part of the "T" connector, the losses to 2.4GHz were amazingly good.

There are 50 ohm and 75 ohm mutations of the BNC connector. I do both radio and CATV, so I have both types on the bench. Todays BNC's are interchangeable between the 50 and 75 ohm types (per IEC 169-8). However, a have a collection of pre 1978 connectors and patch cables, or both types, which are not interchangeable and tend to destroy the receptacle if mixes.

There are also butchers, like me, who insert Type N plugs into a BNC receptacle. It fits, it works, and it easily unplugs itself.

I once made the mistake of designing Amp crimp type BNC plugs into USCG direction finders AN/SRD-21 and 22. Amp claimed they should be waterproof, should survive a salt fog test, and should pass a vibration test. By the time we found out this wasn't quite true, I was stuck with making them work as they could not be easily replaced with something better (i.e. TNC). The fix was cramming a tiny O-ring into the BNC plug, to give a better seal and to provide more pressure to keep the connector from vibrating apart. The down side was that the O-ring was only good for about 10 insertions before it would shred.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

How well do you think that string of adapters would stand up to a passive intermodulation test under some power? Insertion loss and response are not everything.

It would fail miserably. According to several site owners (including the one's I'm involved with), only silver plated or stainless bodies with silver plated pins are acceptable. Nickel plated connectors and gold on top of nickel are horrible. Rectification from dissimilar metals are also a problem with a mix of adapters. I pulled the nickel plated and gold plated connectors out of the system long ago.

Incidentally, I've done the adapter string demo in front of various radio clubs several times. I bring in a large box of random adapters and string them together before the meeting, being very careful to leave out as many UHF connectors as possible. That keeps the losses reasonable and avoids embarrassing surprises.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558