No Stan, you are correct. **True** 75 ohm BNCs (and Ns and TNCs as well) use a substantially smaller center pin and no insulation support around the female contacts. Mating a 50 ohm spec male part (plug) will invariably damage a 75 ohm female (receptacle.)
Amphenol made a **proprietary** series that maintained specs to 4 or so Ghz when mated in the proper system impedance and would reliably interate without damage. This was not a full spec part, but a proprietary variant that was a market response to the damage probelms. They were widely used in broadcast video, and rarely used in RF applications. If need be we can pull the mil drawings as a group and compare them. I learned this lesson by proxy in the days I worked for a cable TV manufacturer and a tech made the mistake for a second time and got his pay docked the repair cost from HP. Fortunately, the parts cost was small. Unfortunately he got to pay for a new cal on the instrument, about 2 weeks pay for him *before* withholding. Rich, N1OZ On 4/9/2011 9:28 PM, Stan, W1LE wrote: > Sorri, I must have been thinking type N connectors. > > Stan, W1LE > > > On 4/9/2011 8:18 PM, [email protected] wrote: >> Interestingly, 50 and 75-ohm BNC connectors have the same pin/shell >> dimensions and properly couple together. For more information go to >> _http://www.cliftonlaboratories.com/august_2007.htm_ >> (http://www.cliftonlaboratories.com/august_2007.htm) and scroll >> down to the 02 August 2007 entry. There is a >> link to the Amphenol site for specifics about the connectors. >> >> I am planning to use an Extron video distribution amplifier for standard >> frequency distribution. The 75-ohm connectors will be OK. These >> amplifiers >> feed multiple 75-ohm outputs from a "zero-impedance" source by >> inserting a >> 75-ohm resistor in each leg. Some folks using these for standard >> frequency distribution change the resistors to 50-ohms. >> >> Bruce, KG6OJI >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- mailto:[email protected] Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
