Now I'm a believer

[marcspaz]

1 minute ago, WRXL702 said:

OMG..... Unbelievable....

Maybe All You Folks Should Consider Talking On Your Radio Stations Instead Of Constantly Arguing, Bickering, & Discussing On How They Are Supposed To Perform...

 

 

1 minute ago, WRXL702 said:

Folks Just Need To Loose Their Attitudes & Share Their Supported Knowledge...

 

How do we "loose" an attitude? And which one is it? Should we stop discussing this stuff or should we share our knowledge and experience? I'm confused. 

[WRXL702]

You Just Posted It.....

Another Attitude - Please Re-read My Post - Or Not......

Peace Out.....

 

[tcp2525]

1 hour ago, WRTC928 said:

So what is the right cable? "You're doing it wrong" isn't helpful information. It might make you feel superior, but it sure as hell isn't going to save me any heartache or money.

As stated above, RG400 MIL spec Teflon dielectric with silver plated copper conductors. Perfect for mobile installation and works great with the world famous and highly cherished NMO mount. In other words, pure perfection. 

And here ya go, an already made cable that's ready for installation and it even has the dreaded PL-259.

https://www.ebay.com/itm/375935266177

[BoxCar]

1 hour ago, tcp2525 said:

As stated above, RG400 MIL spec Teflon dielectric with silver plated copper conductors. Perfect for mobile installation and works great with the world famous and highly cherished NMO mount. In other words, pure perfection. 

And here ya go, an already made cable that's ready for installation and it even has the dreaded PL-259.

https://www.ebay.com/itm/375935266177

The spec sheet for the RG400 cable shows a loss of 28.3 dB at 400MHz per 100 meters. RG8X has a 26.25 dB loss per 100 meters at 400 MHz.

[WRYZ926]

I ran the numbers using the https://kv5r.com/ham-radio/coax-loss-calculator/ for several types of coax. Here are some screen shots showing the losses for 100ft of coax.

LMR400

RG-8X

RG-8

1/2" Heliax

[WRTC928]

12 hours ago, Socalgmrs said:

So you have a ground plane antenna with out a proper ground plane?  Why bother you neutered your antenna.  The whole system is not good at that point.  You probably 1/4erd your tx distance.  All that time and money wrapped up in a bad ground plane makes the rest pointless.  

No, you illiterate. I specifically stated that it's an NGP antenna. But even an NGP antenna can often benefit from a good ground plane.

[tcp2525]

21 minutes ago, BoxCar said:

The spec sheet for the RG400 cable shows a loss of 28.3 dB at 400MHz per 100 meters. RG8X has a 26.25 dB loss per 100 meters at 400 MHz.

Kind of irrelevant since most of us won't be using 100 meters of either in our mobile instalation anyway. Again, using the right coax for the job is key.

[WRTC928]

10 hours ago, tcp2525 said:

RG8x on UHF? Definitely not a optimal choice no matter where it's made. I use RG400 on all my NMO mobile installs. It's quality stuff even if it's made in an Asian country. 

I'll look at that for next time. In the meantime, I'm not having any more line loss than 99% of the installations out there. Less than most, in fact.

[tcp2525]

3 minutes ago, WRTC928 said:

No, you illiterate. I specifically stated that it's an NGP antenna. But even an NGP antenna can often benefit from a good ground plane.

Come on now. Please be civil as this is a family oriented forum.

[WRTC928]

15 minutes ago, WRYZ926 said:

I ran the numbers using the https://kv5r.com/ham-radio/coax-loss-calculator/ for several types of coax. Here are some screen shots showing the losses for 100ft of coax.

LMR400

RG-8X

RG-8

1/2" Heliax

That's nice to know, but LMR400 and Heliax aren't practical for vehicle installations.

[WRTC928]

3 minutes ago, tcp2525 said:

Come on now. Please be civil as this is a family oriented forum.

I'll be civil to him when he stops being an ass.

[WRYZ926]

10 minutes ago, WRTC928 said:

That's nice to know, but LMR400 and Heliax aren't practical for vehicle installations.

I reran the numbers using RG-58, RG-8X, and RG-8 with the length of 15 feet since that is the average length used in vehicle installations.

RG-58

RG-8X

RG-8

 

Now most mobile antennas will not have 5 dBd of gain so you will have to adjust that number using the calculator.

 

[tcp2525]

1 minute ago, WRTC928 said:

I'll be civil to him when he stops being an ass.

Hey, just trying to spread some love. I know some people here might not seem like they love each other, but think of it this way, it can be just as difficult picking the right coax. No shame in selecting the wrong coax, just admitting to yourself you made a poor choice is the first step towards inner peace.

[WRTC928]

2 hours ago, SteveShannon said:

RG58 is used because the dielectric is solid and doesn’t deform like foam dielectrics, but you’re right that it’s even lossier than RG8x. 
Choosing cables for a mobile installation is a juggling act. The only cables that will withstand being pinched in a door are thin and stiff because of solid dielectric materials. But they’re also very lossy. So you minimize the length as much as possible and accept that they aren’t ideal. 

Exactly. So, what's the point of telling me I'm using the "wrong" coax? I'm sure ladder line would give better results, but it won't fit through the holes in the floor of the back of the cab, to say nothing of going under the side bed rail, over the top of the front bed rail, down the front of the bed, under the cab, and back up through the hole in the floor. 15' is about as short as I can go and it has to be very flexible. I'm not aware of anything "better", but I'm open to suggestions. 

[marcspaz]

Im just trying to help and little, but i think there is benefit to watching this video. I put it together for some new Hams in my club, but the Amateur frequencies in UHF are close enough to GMRS, that the demo is still very valid. 

 

 

[SteveShannon]

40 minutes ago, WRTC928 said:

Exactly. So, what's the point of telling me I'm using the "wrong" coax? I'm sure ladder line would give better results, but it won't fit through the holes in the floor of the back of the cab, to say nothing of going under the side bed rail, over the top of the front bed rail, down the front of the bed, under the cab, and back up through the hole in the floor. 15' is about as short as I can go and it has to be very flexible. I'm not aware of anything "better", but I'm open to suggestions. 

I don’t recall ever saying that you are using the wrong coax. I pointed out that RG8x has a foam dielectric and RG58 has a solid dielectric and that’s why RG58 is frequently used for mobile installations.
RG400 also has a solid dielectric and a tiny outside diameter. It’s expensive though. A person could build a Frankenstein cable using RG400 where needed and something with less attenuation elsewhere to make up the necessary length, but the splice points reduce reliability and potentially add losses. 
Also, nothing I’ve said has been demeaning or critical of you or in any way personal. I’ve tried to stick to factual information, demonstrating how I did any calculations. 

[nokones]

10 hours ago, WRTC928 said:

That's nice to know, but LMR400 and Heliax aren't practical for vehicle installations.

Although LMR400 cable is not constructed the same as RG8 coax cable, but they do share the same physical dimensions and RG8 coax was predominantly used in mobiles several decades ago especially when a ball and spring mount was used.

The minimum bend radius spec for heliax in addition to the difficulty of routing heliax throughout a vehicle would make it impractical.

[WRTC928]

56 minutes ago, nokones said:

Although LMR400 cable is not constructed the same as RG8 coax cable, but they do share the same physical dimensions and RG8 coax was predominantly used in mobiles several decades ago especially when a ball and spring mount was used.

The minimum bend radius spec for heliax in addition to the difficulty of routing heliax throughout a vehicle would make it impractical.

The stiffness of RG8 is specifically why RG8X was invented. It would be extremely difficult, if not impossible, to route LMR400 in most of the ways required in a vehicle.

[WRTC928]

It did occur to me after reading some comments that because this is a NGP antenna in a NGP installation, perhaps the real difference is that the cable I changed to acts as a better counterpoise than the one I replaced. That could simply be a fluke, because I doubt either US or Chinese manufacturers give any significant thought to its characteristics as a counterpoise. Maybe they do, but I'd be a little surprised.

[WRUE951]

1 hour ago, WRTC928 said:

The stiffness of RG8 is specifically why RG8X was invented. It would be extremely difficult, if not impossible, to route LMR400 in most of the ways required in a vehicle.

Not all RG8 is stiff..  Radio Shack used to sell a flex RG8..  I've used it many times and yes it is flexible.  It was a pain to make connectors though,  the dielectric would stick to the center conductor which had to be scraped with a plastic wedge and the shielding would mold into the outer sheath making that a pain to remove.  But over all after spending an hour putting connectors on, it was decent cable  

[tcp2525]

9 minutes ago, WRUE951 said:

Not all RG8 is stiff..  Radio Shack used to sell a flex RG8..  I've used it many times and yes it is flexible.  It was a pain to make connectors though,  the dielectric would stick to the center conductor which had to be scraped with a plastic wedge and the shielding would mold into the outer sheath making that a pain to remove.  But over all after spending an hour putting connectors on, it was decent cable  

The words "Radio Shack" totally disqualifies this as a viable choice. At least you got a free battery if you joined the battery of the month club. But seriously,that cable was acceptable for CB use, that's it. 

[WRYZ926]

One of the main differences between cheap coax and more expensive quality coax is the amount of shield braid used and also the materialist is made from. You will only see about 50-60 percent of the dielectric being covered by the shield braid on cheap coax where you will see 70 to 100 percent coverage in the more expensive coax.

The amount of shield braid makes a difference in how it protects against RFI and will also act as a better counterpoise when the coax is used as such. 

It is common to use the coax as a counterpoise when using end fed half wave antennas for HF versus running a separate counterpoise wire.

[WRUE951]

1 hour ago, tcp2525 said:

The words "Radio Shack" totally disqualifies this as a viable choice. At least you got a free battery if you joined the battery of the month club. But seriously,that cable was acceptable for CB use, that's it. 

well there sonny,,,  There was a time when Radio Shack was the deal...  Unless your an old timer, you have no clue... 

[tcp2525]

1 hour ago, WRUE951 said:

well there sonny,,,  There was a time when Radio Shack was the deal...  Unless your an old timer, you have no clue... 

As kids we hung around the local RS before the TRS80 computer was even thought of. Their parent company, Tandy, used to sell leather and leather crafting tools back then. Their coax sucked and I didn't even know what good coax was. We used it for CB because we didn't know any better. 

Actually Lafayette was a much better and highly respected company. 

[SteveShannon]

48 minutes ago, tcp2525 said:

As kids we hung around the local RS before the TRS80 computer was even thought of. Their parent company, Tandy, used to sell leather and leather crafting tools back then. Their coax sucked and I didn't even know what good coax was. We used it for CB because we didn't know any better. 

Actually Lafayette was a much better and highly respected company. 

You’re just a young guy!

Before Tandy Radio Shack there was Allied Radio Shack and before Allied Radio Shack there was Allied Radio and Radio Shack, two separate companies. Allied Radio was a well respected competitor of Lafayette. 
Not everything sold by Radio Shack has been poor quality. They even sold some reasonable quality coax but they also sold some crappy coax as well. 
Personally I prefer to stay away from inexpensive coax. I would rather use quad shielded RG6 for UHF, even at 75 ohms, than some of the lossy 50 ohm cable.