Com Radio RG400 Extenson Cable?

[jaustinmd]

I have a MGL V6 com radio that I really like except the frequency fonts are difficult to read from an off-center angle. I'd like to move the radio to an available mounting hole almost dead-center in front of me, but my RG400 antenna cable is too short to make the move, even if I switched to a right-angle connector. Is it permissable to add a BNCmale/BNC female RG400 extension cable approximately 1 ft. long? I've searched the 'net and haven't found any information about this at all. I would guess that each additional connector opens a possiblity for some loss and noise, but would it be OK to at least try it and see how it works, OR, is this a really bad idea for some technical reason?

By the way, there's NO WAY I'm going to reroute another, longer RG400 antenna through my airframe to the antenna! LOL! I'd rather suffer with the radio as-is than suffer through that! HA!

Regards,
John
N750A

[Auburntsts]

Don't see how it would be a problem. The worst that could happen is some signal loss due mostly to the added BNC connectors. There's probably a more elegant way to "splice" in the extra foot, but your solution should work just fine.

[Neil]

Been there and done that. Not anything to worry about.

[Mark]

The typical loss for a BNC connector is 0.1 * sqrt(freq-GHz) dB
So at R/T frequencies it's about .03 dB - not a lot.
That's equivalent to about another foot of RG400 or 6" of RG58.

[FlyingRon]

As pointed out the loss will be of small consequence and it's going to be the connectors rather than the extra foot of RG400. One thing that can be handy if you can swing it with the existing cable slack is to loop the cable down so that the connectors between the original wire and the extension can be reached from the cockpit semi easily. Then you can get another short extension for your handheld and in case the panel dies, you reach up, unplug the extension going to the panel mounted radio and plug in your handheld and get to use the external antenna.

Neat trick Bill Needy used to do on his installations up at HGR.

[jaustinmd]

As pointed out the loss will be of small consequence and it's going to be the connectors rather than the extra foot of RG400. One thing that can be handy if you can swing it with the existing cable slack is to loop the cable down so that the connectors between the original wire and the extension can be reached from the cockpit semi easily. Then you can get another short extension for your handheld and in case the panel dies, you reach up, unplug the extension going to the panel mounted radio and plug in your handheld and get to use the external antenna.

Neat trick Bill Needy used to do on his installations up at HGR.

Fabricated the cable with quality (Amp) connectors and I could detect no difference in reception or noise at all! That's a neat trick about using the external antenna for the handheld - I had suspended the cable with a zip tie at the site of the extension connection - think I'l change that to a Velcro strap, making it easy to just unfasten the Velcro and disconnect the male/female connectors. My original cable should easily pull forward to the bottom edge of the panel. I'll fabricate another extension for my handheld so I can use that as a backup radio. Great idea!