MX350 BNC Adapter Video

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WA6OXN
Posts: 81
Joined: Tue Nov 13, 2007 7:55 am
What radios do you own?: Saber, Astro Saber, Micor, Mot

MX350 BNC Adapter Video

Post by WA6OXN »

I bought one of those BNC to MX threaded adapters on Ebay and made a short video with what I found.

Not good... Search continues for a BNC threaded adapter.

I do have the one that goes on the side and interfaces to the antenna connector, but I have a bunch of BNC antenna's around so thought this might work.

https://youtu.be/WTfksDShipI

-Steve
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escomm
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Re: MX350 BNC Adapter Video

Post by escomm »

Check out RF Industries p/n RFB-1145
RadioSouth
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Re: MX350 BNC Adapter Video

Post by RadioSouth »

It appears this type of adapters picks up the center pin only, no ground (unless that outer shell is supposed to be contacting the metal escutcheon of the radio) ? and would that even be a RF ground connection ?
I recall a discussion years back about the HT600/MT1000/Saber with this type of antenna stud adapter and the consensus was that they don't work and that RF needed to be tapped from the accessory connector to pick up the RF hot and ground.
Will
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Re: MX350 BNC Adapter Video

Post by Will »

There was a mod that grounded the top or escutcheon.
mike m
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Re: MX350 BNC Adapter Video

Post by mike m »

With the MT1K/P200 you can make an adapter that connects the center conductor only of the bnc antenna to the antenna stud; however, as Will says you need a ground from the outer side of the bnc to a close radio ground point.

On the MT1K/P200 LOW BAND MODELS I use the screw terminal of the TOP UDC plastic cover.

I use this method on my MT1K/P200 low band models to an outside antenna and for use with a 33 inch low band bnc antenna and it works well.

I also use this on my MT500 low band models and when I measured both of my MT500 10 N 6 METER models using a hp8753 network analyzer and a home brew stud to bnc arrangement, the return loss was better than -10db and this was even better than using the intended 50 ohm antenna jack on the MT500.

When I did the MT1000/P200 low band 6 meter conversion doc I surface mounted a sma connector at various points in the radios PA and receiver chain to come up proper LC values for 6 meters.

When I was all done with my conversion document I went back and used my homebrew stud to bnc adapter and measured a very good S11 value on the receiver and also over 7 watts of TX output, but only when I grounded the BNC outer connection to the MT1000 udc hold down screw with as short and direct a connection as possible.

I also go the opposite direction with a similar stud to bnc adapter so I can use a MT1000 6.5 inch LOW BAND helical on my Azden AZ61 HANDHELD and it works much better than any of the numerous tuned bnc 6 meter antennas in my collection.

I don't remember if the saber has a close ground point or not but if it does then such an adapter should work.

I loaned my bnc-stud adapter out but if I can get it back then I'll try and take a pix of it.
WA6OXN
Posts: 81
Joined: Tue Nov 13, 2007 7:55 am
What radios do you own?: Saber, Astro Saber, Micor, Mot

Re: MX350 BNC Adapter Video

Post by WA6OXN »

Thanks, I'll check it out.
escomm wrote:Check out RF Industries p/n RFB-1145
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