BNC cables, terminators, Tees, etc.

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Richard Hull
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BNC cables, terminators, Tees, etc.

Post by Richard Hull » Wed Aug 22, 2001 8:47 pm

Marlin P. Jone and Assoc, Inc at

http://www.mpja.com

has a good selection of BNC cables, connectors, adapters and terminators.

On page 35 of their current catalog, they have a BNC 50 ohm professional terminator for $2.49, a BNC f-m-f tee for $2.25 and twist on male connectors for $1.50.

They also have other electronic goodies I have used.

They offer a nice sized, bright, LED digital panel meter (part # 12308-ME $12.95 each) which reads in volts (200 millivolts), but can be scaled to read any voltage. I used two of these in my fusor III set up to monitor current and voltge from my converted X-ray supply. (see my web page)

For those rolling their own counters, etc., they have a nice LED three digit counter kit (999 counts) which can be used in any cobbled up counter system. (part # 6001-KT $15.86)

I also am working up a vacuum system control built around their 12 bit data acquisition system. This boasts 4 ditigal bit inputs, four digital bit outputs. and (8) 12 bit multiplexed, A-D converter inputs. This is also a kit with complete software included (8418-KT $55.00)

This should help some of you hardware types out a bit.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Tom Dressel
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Re: BNC cables, terminators, Tees, etc.

Post by Tom Dressel » Thu Aug 23, 2001 5:26 am

Richard

Whot did you call those special high voltage BNC like connectors? I remember you said that they are expensive and never found on the surplus market. But I cant find your post on the connectors. It may have been on an IDJ post that was deleted.

Where can I find the connectors an the high voltage cable?

Tom Dressel

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Re: BNC cables, terminators, Tees, etc.

Post by guest » Thu Aug 23, 2001 6:12 pm

The connectors are two types. MHV BNC and SHV BNC Most NIM stuff I have seen goes straight for the SHV BNC on supplies and the like. However, most geiger counters and portable apps go for the MHV BNC.

Larger Neutron counter tubes and the like use an even wierder and more expensive HV connector, the HN connector, with cables here costing over $100.00 in some situations.

All these connectors use standard HDPE insulated RG-58 cable which can withstand the tension.

There is no hard and fast rule, but most gear with voltages under 500 volts can use the BNC and those up to 1000 or even 1500 volts use the MHV. Above 1500 volts and up to 5000 volts, the SHV is used.

On personally designed stuff I have shipped 1200 volts through common BNC connectors and have routinely removed MHV plugs from geiger counters and ratemeters, replacing them with teflon insulated common BNC jacks.

The only real supplier I have seen for these bizarre BNC connectors and cables is Pasternack Enterprises

http://www.pasternack.com

Hold on to your wallets guys!!

A 3 foot long SHV male plug to male plug cable is $66.68!!
The MHV cable of the same type and same length is a steal at $33.68

Where is radio shack???

The raw SHV crimp plug is $20.95 each!! DO NOT SCREW UP YOUR ONE SHOT AT THE CRIMP!!!

Smart money flys BNC all the way provided you don't need over 1500 volts.

A very wise first buy is an adapter!!

For most NIM stuff this is pasternack #PE9265 ($64.95) this is a SHV plug to MHV jack.... you are now down to using the $33.68 cable. Into this you might even plug their # PE9297 ($23.95) adapter which is a MHV plug to BNC female jack. Now you are using $3.00 BNC cables. So for only $90.00 you can avoid buying a $66.00 cable. Actually it is better than this, for with the adapters, you can plug BNC cables into any oddball SHV or MHV situation you encounter, pretty much.

If you run into an MHV jack, just stick in the second adapter mentioned above and go BNC from there. If you slam into an SHV jack, just couple both adapters above together and use common BNC cables. This will not fly well with the neutron counter tubes (He3 or BF3) as they often need 2300 volts on them. DO NOT USE BNC CABLES HERE!

Most of the stupid SHV BNCs are encountered on NIM bias supplies which can go to 5kv max. If you are only going to 800 volts for a geiger tube or 1000 volts for a PMT, then use adapters and a BNC cable!

The other solution is to alter the item itself by removing the SHV connector and installing a MHV bulkhead connector in its place #PE 4193 ($10.95) and then adapt with the cheap adapter to BNC. Most all MHV type gear, (geiger counters and the like), can be down graded to regular BNC bulk head connectors # PE4010 ($4.95).

Another rule of thumb is you can carefully down grade one connector notch in a controlled, moisture free, clean environment. The exception is if you are using a 5000 volt variable supply which demands and uses an SHV connector but you only need to get 800-1000 volts, then feel free to adapt down to BNC cabling. I would never alter the original connector here though as it is required if the instrument is to be used in future for voltages over 2kv.

No matter how you cut it, MHV and SHV cabling is almost a federal government purchase item. Even for we poor experimenters, the adapters to use affordable cabling are a near $100.00 hit in the wallet.

Richard Hull

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Re: BNC cables, terminators, Tees, etc.

Post by r_c_edgar » Thu Aug 23, 2001 6:42 pm

Richard - there was a minor typo in the link you placed in the above post, so it went to a completely unrelated site, instead of Pasternack Enterprises.

I went ahead and fixed it to point to the correct address.

-Ryan Edgar

Tom Dressel
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Re: BNC cables, terminators, Tees, etc.

Post by Tom Dressel » Thu Aug 23, 2001 8:42 pm

Can you tell what kind of connector it is by looking at them?

The upper left, upper right and middle left are Standard BNC connectors.

The lower left connector is on the input of the high voltage "passthrough" on a proportional counter preamp and is listed as a SHV BNC.

The question is what is the connector on the lower right? It is on the output of a Bertan 0-10 KV power supply. Is it a MHV BNC or the moer exotic (expensive), HN connector?

Tom Dressel

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Re: BNC cables, terminators, Tees, etc.

Post by guest » Fri Aug 24, 2001 3:38 am

The high voltage input connector is an SHV. These are commonly what you will see on a lot of the newer equipment, as they cannot be mixed up with ordinary BNCs. Alas, they are harder to get than MHV connectors, which are the other high voltage BNC type. Hamfests and or surplus is one route (slow but cheap). If you are in a hurry, try someone like Digikey (expensive) or Pasternak Enterprises (merely outrageous rather than rape-and-pillage).

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Re: BNC cables, terminators, Tees, etc.

Post by Tom Dressel » Fri Aug 24, 2001 2:59 pm

Yes, the high voltage input connecter is an SHV. But what is the high voltage connector, lower right, on the OUTPUT of the High voltage power supply?

Tom Dressel

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Re: BNC cables, terminators, Tees, etc.

Post by guest » Fri Aug 24, 2001 5:16 pm

Can you post a more oblique view of the HV connector? It looks longer than the standard BNC. If it is, it may be a 10kV class MHV, but I'm not sure at this point.

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Re: BNC cables, terminators, Tees, etc.

Post by Tom Dressel » Fri Aug 24, 2001 8:10 pm

Here is the oblique view of the 10 Kv output. Anyone know what kind of jack it is and what kind of cable it takes?

Tom Dressel

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Re: BNC cables, terminators, Tees, etc.

Post by DaveC » Sat Aug 25, 2001 12:30 am

I have seen MPJ 's stuff and they have some excellent prices. I have found that the local big electronics store matches their prices...on most hardware...they probably all get it at the same places.

They MPJ also have a good selection of mini-video cameras (color and B/W) for cheap. good to be on their mailing list.


Dave Cooper

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