What's this?

[cjmitchell5]

So I started thinking about CB's and 2m radios for the truck. I knew my truck had an antenna base on the roof but I never looked closely at it and figured it had been for a CB radio. Nope, it appears to be a 70cm antenna. So here are a few pics of what I'm looking at if someone can enlighten me

One photo is of the power supply plug. Are power supplies brand specific or generic?

The next photo is of the antenna plug where it connects to the unit.

And two photos of the antenna base. It has a company logo that I'm not sure who that is and on top it's molded w/ 406-470 mhz.

Thanks! I know nothing about CB's or HAM other than what I've learned on ExPo So whatever you can tell me is appreciated!

 

[Luke]

You should be able to screw a lot of different antennas onto that base. 2m, 70cm, multi-band, 1/4 wave, 1/2 wave, etc. The power clip is different than my Yaesu power clip so I'm not sure what it is. FWIW

 

[gary in ohio]

One photo is of the power supply plug. Are power supplies brand specific or generic?

Its hard to tell the size of the wire but its most likely not big enough for the 2m rig, but would be ok for CB. Most likely neither radio will have the same plug as what you have.

The next photo is of the antenna plug where it connects to the unit.

The second photo is a crimp on pl259 connector, It tells you nothing about
the band or frequency.

And two photos of the antenna base. It has a company logo that I'm not sure who that is and on top it's molded w/ 406-470 mhz.

The base will tell you little about the frequency, but more about the mounting method. Can you unscrew the base and give us a photo of whats under the base. Most likley its a NMO mount and with that you can pretty much put any band antenna on.

 

[DaveInDenver]

I'd have guessed that the connector was a Molex VersaBlade, but without seeing it up close it's hard to tell for sure. It's not quite the same, the locking tab is a little different, so it could certainly be a knock-off of Molex, AMP or other major manufacturer and so it won't be identical.

http://www.molex.com/molex/products...RIMP_HOUSINGS.xml&channel=Products&Lang=en-US

The base will tell you little about the frequency, but more about the mounting method. Can you unscrew the base and give us a photo of whats under the base. Most likley its a NMO mount and with that you can pretty much put any band antenna on.

Even if you know it's NMO, without knowing if it has a something in the base, you can't say what band it'll work on. If there's no caps or inductors, then it'll be tuned by whatever antenna whip you put on it. But if the base has an impedance matching network or a loading coil, then it's usefulness is limited without some tinkering.

 

[teotwaki]

if you look at the picture of the base you'll see faint letters "a" and "s"
for the company Antenna Specialists. No longer an independent brand, they were bought out by PCTEL.

Looks to be a pretty old style so can we see a picture of the 400 MHz whip portion? They used to have spring loaded bases and were center loaded half waves.

 

[gary in ohio]

Even if you know it's NMO, without knowing if it has a something in the base, you can't say what band it'll work on.

Sure you can, Your going to throw away the existing base with any antenna you install so only the mount type matters.

 

[DaveInDenver]

Sure you can, Your going to throw away the existing base with any antenna you install so only the mount type matters.

I guess I'm still not fully engaging my analog brain (been doing some VHDL coding this morning and I got my digital gears cranking!). But if I knew I had the base from a Larsen NMO 2/70 but no whip, I'd sure prefer to buy a $15 whip instead of a whole new $60 antenna. I believe that Larsen example has an impedance correction network in the base and it would not be much use if you spun on a 1/4 wavelength whip. But since this one is probably a commercial antenna base, I'd guess that it was designed for a 1/4 wavelength whip, so there might not be anything in the base in this case.

 

[gary in ohio]

That base isnt a 2/70 base, It has a thread output so going a buying a whip for it itsnt going to happen. As has been noted it looks like an antenna specialist antenna and they were purchased by PCTEL. From my quick check all the PCtel antenna are NMO non have a base like is shown. ON top of that I beleive A/S was purchased almost 10 years ago, so the antenna base is getting old and most likey should be replaced with something modern, of a known brand where spare parts are available.

your correct, if it was something like a 2/70 then a whip would have been a good solution.