All About the 7/16 DIN connector

These connectors appear on the backs of various FM and lower-power TV transmitters. I thought it would be interesting to explore them a little bit.

First, according to Wikipedia, DIN is an abbreviation for Deutsches Institut für Normung. If you enjoy a lager or two then squint at that name you might see The German Institute for Standardization. 7 is the size of the inner conductor contact in mm and 16 is the size of the inside diameter in mm of the outer conductor. The thread is 29 x 1.5 mm.

From what I can find, the connector was originally developed for the German Military, which needed a rugged, efficient connector that was easy to install properly.

This style of connector is very popular with cellular antenna manufacturers due to its relatively high power handling capability and excellent passive intermodulation performance.

According to Amphenol, their 7/16 DIN connectors have the power handling capability of 3000 watts/1 GHz @ 25C (77F). That is a fairly low temperature. They give the working voltage as 500 V RMS continuous, which is 5000 watts at 50 ohms impedance. That, of course, assumes a 1:1 match, which is never the case. The connector is probably safe to ~2 KW in normal operating conditions for VHF and UHF TV operation.

Amphenol 7/16 plug for LMR-400 and Belden 9913

Also, keep in mind that RG-8, RG-213, RG-214, LMR-400, and Belden 9913 look similar but they use different connectors because the inner conductor of the latter two is larger than RG-8, RG-213, or RG-214. This happened on a project recently. It came time to crimp the pin on the center conductor and, oh no! The pin was too small!

A properly installed connector will be outdoor water-resistant in most weather conditions.

6 thoughts on “All About the 7/16 DIN connector”

  1. Years (& years) ago got a military Discone antenna with a 7/8 DIN connector on it. “What the hell is that!?” Lucky for me it came with a connector on a short piece of MIL 214 coax. I was able to cludge an N connector on it.

  2. I prefer to have a DIN connector on an antenna outdoors over an N connector. On a recent LPFM antenna I installed, I specified for the connection to be a DIN due to the overall strength and issues that develop with N connectors.

  3. Funny the cultural differences. In places where the metric system has predominated for a long time, a slant bar between two numbers is seen as a whole number delimiter. In places using inch-pound measuring systems, fractions are used, so the slant bar is seen as a fraction delimiter. Thus, “7/16” is 7-sixteenths in most folks minds in the US when first seen.

    That 7/16 DIN connector reminds me of one we used in my USAF days on high power HF transmitters, Type LC. Saw it on Collins “URG” 208U-3’s mostly. I guess LC has disappeared long ago.

  4. I’ve always been leery of these tower men putting on connectors that they may have never seen before. Did they do it right? Is it sealed from the elements? Perhaps I should go up there and check it out.

  5. Lou, I was taught to always have the factory install the connector on the antenna end of the spool of cable, so that the tower crew would only assemble the connector on the ground at the transmitter. That usually avoids a lot of grief.

  6. Crusty, the first time I saw a 7/16 DIN I thought, what an odd looking LC connector. It didn’t take long to figure out that it was something new.
    There are also “mini-DIN” connectors which come in 4.3/10, 4.1/9.5 and 1/2.3 sizes. This first time I ran into a 4.3/10 was on a mountain top working on a LP UHF TV transmitter. Naturally, I needed an adaptor that I didn’t have.

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