AS-1729/VRC antenna cb conversion

[notsosanestan]

Military Antenna Conversion for CB

has anyone tried to do this? i got the base and antenna and am ordering the antenna bracket today. im new to radios trying to learn i just dont understand what he means when he says bring a hot to the antenna is that just the antenna wire from the cb? i know it has another plug for the mil radio so im a bit confused i figured that plug would power it.

 

[emmado22]

His "hot" is the antenna wire. The RF connection on the antenna base is a BNC connection.

 

[tennmogger]

Most anything you hook coax to will radiate some signal, and if you manage to tune it for low enough reflected power, the radio won't mind.

But, why would anyone tune an antenna, much less a pair of antennas, 'off' the vehicle they will be used on? Why connect two antennas in parallel without matching their combined 25 Ohm (two 50's in parallel) combined impedances back to 50 Ohms resistive? IMHO it's easy to understand why he didn't get the SWR below his estimate of "somewhere between 2.1 and 3".

It looks 'military-ish' on the hummer, and that's what he was after.

A single AS-1729/VRC, tuned down to 26.5-27.5 MHz for CB (doubt if it'll tune that far) might work ok. I haven't done it but you sort of asked for advice LOL. Maybe I should try to tune one of my AS-1729/VRC's before I yack too much...but don't want to waste the antenna.

Keep in mind that an AS-1729/VRC is not a simple quarter-wave whip but a center-fed coaxial dipole so will not respond well to trimming the antenna length.

My first choice for CB or any other frequency outside the band normally covered by the AS-1729/VRC, would be a simple insulated base and enough MS-116s, MS-117, and MS-118 sections to add up to needed quarter wave on 11 meters (about 110 inches including the spring and upper portion of the base). That combination will tune down to zilch reflected power....approaching 1 to 1 SWR

Bob

Military Antenna Conversion for CB

has anyone tried to do this? i got the base and antenna and am ordering the antenna bracket today. im new to radios trying to learn i just dont understand what he means when he says bring a hot to the antenna is that just the antenna wire from the cb? i know it has another plug for the mil radio so im a bit confused i figured that plug would power it.

 

[Chief_919]

Most anything you hook coax to will radiate some signal, and if you manage to tune it for low enough reflected power, the radio won't mind.

But, why would anyone tune an antenna, much less a pair of antennas, 'off' the vehicle they will be used on? Why connect two antennas in parallel without matching their combined 25 Ohm (two 50's in parallel) combined impedances back to 50 Ohms resistive? IMHO it's easy to understand why he didn't get the SWR below his estimate of "somewhere between 2.1 and 3".

It looks 'military-ish' on the hummer, and that's what he was after.

A single AS-1729/VRC, tuned down to 26.5-27.5 MHz for CB (doubt if it'll tune that far) might work ok. I haven't done it but you sort of asked for advice LOL. Maybe I should try to tune one of my AS-1729/VRC's before I yack too much...but don't want to waste the antenna.

Keep in mind that an AS-1729/VRC is not a simple quarter-wave whip but a center-fed coaxial dipole so will not respond well to trimming the antenna length.

My first choice for CB or any other frequency outside the band normally covered by the AS-1729/VRC, would be a simple insulated base and enough MS-116s, MS-117, and MS-118 sections to add up to needed quarter wave on 11 meters (about 110 inches including the spring and upper portion of the base). That combination will tune down to zilch reflected power....approaching 1 to 1 SWR

Bob

I agree.

The CB crowd loves to run twin antennas thinking it gives them some gain. twin 1/4 antennas, in free space, fed in phase, with the proper spacing will indeed provide a directional pattern. But his are not 1/4 wave, not in free space with that metal between them, and not spaced properly.

In addition the gain figures for those antennas when they are in band are expressed in negative gain numbers. He took antennas that suck anyway, tuned them outside the range they are designed for for even more suck, then failed at trying to phase them as a pair for yet even more suck.

I agree with you on the MP-68 base and the MS-116,117 and 118 mast sections. Cut to 1/4 wave on 11m it works great- it will be far better than what he did at that link and it is still military.

 

[notsosanestan]

I am not using two antennas I also don't use my CB much only offroadig with friends I Just want the military look on my m1009

 

[notsosanestan]

I am not using two antennas I also don't use my CB much only offroadig with friends I Just want the military look on my m1009

 

[badassissimo]

I'm in this same boat. Is there an antenna that uses a long whip and similar base that is able to connect to a CB? Not sure if I would be able to tune an antenna or even find someone. Not sure it would be very compatible afterward anyhow.

 

[SCSG-G4]

As was previously said, use an MP-68 base instead of the AS-1729/VRC, and then use a combination of the MS-116, -117, and -118 antenna sections to achieve the total length of 110 inches. Manually set the MP-68 base down as close to the CB frequency as possible (30-33 Mhz is about as low as it goes - I just looked). BTW, the MP-68 base tuning knob only turns one way, so don't force it!

 

[mikev]

I'm in this same boat. Is there an antenna that uses a long whip and similar base that is able to connect to a CB? Not sure if I would be able to tune an antenna or even find someone. Not sure it would be very compatible afterward anyhow.

Me too meaning I have the mount, antenna base and antenna and would like to hook it up as a CB antenna...

Reading this thread, so far appears to not be "feasible" with the USGI antennas that were used on the M1009 CUCVs?

Any other experts out there with CB/mil radio/antenna advice? I know mechanics, but commo is my weak point...

 

[mikev]

As was previously said, use an MP-68 base instead of the AS-1729/VRC, and then use a combination of the MS-116, -117, and -118 antenna sections to achieve the total length of 110 inches. Manually set the MP-68 base down as close to the CB frequency as possible (30-33 Mhz is about as low as it goes - I just looked). BTW, the MP-68 base tuning knob only turns one way, so don't force it!

Thanks Mike - you replied while I was typing...

I'll check the set-up you recommended!

 

[mistaken1]

When you tune the MX67 for CB. You do it by tuning the impedance matching network not trimming the antenna.

It can be done. You can get the SWR fairly low as well (under 1.5:1 as I recall). Not to say that it is a great performing antenna but it will let you look military and still communicate over short ranges.

I replaced my unused CB with a 100watt Midland Syntech II retuned to 6-meters and so I am using the MX6707 on a different band. Looking at the schematic I need to send power to the base to get it to switch to a different circuit that will be closer to my output an that should drop the SWR some more.

 

[m38mike]

If you want good CB performance from a military antenna, here's a combination that works really well. Get an AB-15 base, or a MP-65-b base. Both of those have the correct connectors for a common CB coax cable with PL-259 connectors to mate with. For antenna sections you want 2 longs and a short antenna section. So that could be an MS-116, MS-117, and a GR-24. That's what I use on my M38 and it works great. The MS-### are about 36 inches long and the GR-## are about 22 inches long. Combined with an AB-15 or MP-65 they measure about 106 inches which is almost perfect for a CB. The important thing is that you need two MS-### sections and one GR-##. No cutting involved. Just screw the sections togther and start talking. On my M38 this combo gives me an SWR of 1:1.3.

 

[jmassenga]

I have a AB558 base and MS116, 117 & 118 for an antenna. This is connected to a splitter and a original (civvy) Delco AM/FM/CB radio in the dash. The AB558 takes a standard coax connector, so setup was easy and no permanent modifications were required. While perhaps not perfect, I can send, receive, and listen to the radio with this combo, so it meets my needs.

 

[cucv1833]

This is great info. I just intalled a Cobra Classic 29 and the fender mount with a AB-15 base and the MS-116-117-118 and cut it down to a total of 108 inches im getting a good signal i had not not tested the ranges yet but i think my SWR is
1:1.3 its on my M1009

 

[Flyingvan911]

That's a great SWR!!!

 

[epitts]

What would be the best wip antenna for the 118-136 mhz range?

Thanks

 

[tennmogger]

Military? Non Mil? Fixed mount? OD?

Most simple antenna would be a little whippy whip about 2 ft long on a mag mount.

If you transmit there on the aircraft band then tune the antenna, otherwise receive will do just fine without tuning.

Bob WB4ETT

 

[epitts]

Military? Non Mil? Fixed mount? OD?

Most simple antenna would be a little whippy whip about 2 ft long on a mag mount.

If you transmit there on the aircraft band then tune the antenna, otherwise receive will do just fine without tuning.

Bob WB4ETT

Sorry for not making myself clear. I will mount it on my M1009 in the stock antenna mount. Would like stock military looking Whip antenna. Need not be OD. Will transmit also.

 

[cucv1833]

Sorry for not making myself clear. I will mount it on my M1009 in the stock antenna mount. Would like stock military looking Whip antenna. Need not be OD. Will transmit also.

I just did the research on this page and bought the AB-15 base the MS-116-117-118 off eBay about $100. The total length of all this was over 120" so I read 106-110" was good so I cut my to 108" and checked the SWR reading on my CB and it's all good I'm am very happy with the look and it seems to work well for what I need if you want non military just go to a truck stop and pick up a whip
Good luck

 

[tennmogger]

Hi Eric,

To use your stock mount (what type?), if you can find any kind of base insulator that fits your mount (AB-15 type, or many other bases like it), then add a short antenna. Since you only need a short radiating element, I think I'd use a piece of thin 1" tubing, adapted to clamp to the base spring, and cut that for minimum reflected power. You could hose clamp it around the outside of the top of the stinger on the base. The large diameter will widen the SWR minimum and you might get a good match over the whole band. Seal the top with a plastic cap or crutch tip, and paint it OD. I think that'd look cool, and I know it'd work well.

BTW, a switching base like MX-6707 for AS-1729 antenna would not work.

Bob WB4ETT