COBRA 29 with IRF510/ IRF520 / ERF2030 Question

[RFEverywhere]

You're doing absolutely everything wrong, even running the negative wire directly from the battery which is an absolute no-no yet most people do it.

Please elaborate. How and why am I doing everything wrong captain?

In regards to my negative power line, please re-read my post. It is not coming from the battery. It is coming from the metal body of the car. However, even if it was coming directly from the battery terminal, why is that considered wrong and how does that impact the system in a negative manner?

Low SWR does not equal efficiency. Don't be fooled by thinking a low SWR means its working properly. You use a MFJ antenna analyser. What does tell you how efficiently it is working is the value of R when X=0, the resonant point of the antenna. Should be 37 Ohms for a perfect installation. Anything above or below that shows you've got losses. If you're getting near 50 Ohms where X=0, you've got a whole lot of losses.

Agreed!!!! Quite honestly I don't remember what the efficiency was. I think it was +/- 50 ohms while resonant on my center frequency. Can you please explain why R or the resistance should not be 50 ohms and rather 37 ohms?

Jesus!!!!! Just when you think you know Jack someone comes along and makes you realize that you only know of Jack.

No idea why you need an amp on the Baofeng. 10W on my installation in my car gets me 60 miles easily.

I don't know how you are getting 10W out of your Baofeng . Which model do you have? I have both the 5R and 82 model and both put out around 3W to 3.5W even though the 82 is suppose to have a little more juice. The only repeaters I have hit without the amp is about 15 air miles away and unfortunately there is no others around here that are within 20 to 50 mile range to test. To me, 60 miles sounds reasonable with about 10W on VHF/UHF. And let me tell you... I know this because I am very knowledgeable. Something tells me that you are not using the factory antenna which by the way, I tested it with the antenna analyser and sure as heck, it's their POS version. Was not resonant anywhere from 2MHz to 175MHz. Maybe on 70cm but not on VHF.

Excuse all the questions. I only have all the radio gear and test equipment. I am trying to learn more about this hobby so I can start using everything properly.

Never watched any cop shows hey? MO= modus operandi which means the way in which someone characteristically does something.

10-4. Copy that.

No.....not really. In fact he was somewhat of a real dickhead troll actually.

Huh!!!!! Sounds like he/she is a really cool cat.

But really though....Dickheads can be smart people... On the other hand, you are right they just think they are and my brother-inlaw is the perfect example of that....

F#&*ING DICKHEAD. I promised myself that everytime I thought of him (my brother inlaw), I would use the word dickhead.

 

[M0GVZ]

Please elaborate. How and why am I doing everything wrong captain?

In regards to my negative power line, please re-read my post. It is not coming from the battery. It is coming from the metal body of the car. However, even if it was coming directly from the battery terminal, why is that considered wrong and how does that impact the system in a negative manner?

Apologies, I misread that part. Why it is wrong is that if you have a fault in the main battery cable from negative to car body, if you've connected your radio to the battery negative terminal, because there's a path to the car body the entire current of every device in the car which uses the body as a ground connection will flow through your radio.

Agreed!!!! Quite honestly I don't remember what the efficiency was. I think it was +/- 50 ohms while resonant on my center frequency. Can you please explain why R or the resistance should not be 50 ohms and rather 37 ohms?

Because at resonance (x=0) that is the input impedance of a 1/4 wave vertical antenna over perfect ground and that is what we want to be replicating. If you see 50 Ohms at resonance its either because of a crap antenna design or a less than optimal installation. You see 50 Ohms because of losses. You should see 50Ohms a few kHz away from where X=0. The lowest SWR and resonant point are never in the same place except where there's substantial losses.

I don't know how you are getting 10W out of your Baofeng . Which model do you have? I have both the 5R and 82 model and both put out around 3W to 3.5W even though the 82 is suppose to have a little more juice. The only repeaters I have hit without the amp is about 15 air miles away and unfortunately there is no others around here that are within 20 to 50 mile range to test. To me, 60 miles sounds reasonable with about 10W on VHF/UHF. And let me tell you... I know this because I am very knowledgeable. Something tells me that you are not using the factory antenna which by the way, I tested it with the antenna analyser and sure as heck, it's their POS version. Was not resonant anywhere from 2MHz to 175MHz. Maybe on 70cm but not on VHF.

I assumed you were using the Baofeng with an external antenna. 5W won't halve the range of the 10W I mentioned and 60 miles is pretty much the limit for most people because of the radio horizon. You could put out 1000W and you'll still only get the same distance.

 

[GnG8d]

Connor, do you actually understand the real and imaginary parts of impedence?

 

[M0GVZ]

Connor, do you actually understand the real and imaginary parts of impedence?

Rr, Rc and ground loss? Pretty much.

Hardest part is trying to explain it in ways other people can understand.

 

[binrat]

Please elaborate. How and why am I doing everything wrong captain?

In regards to my negative power line, please re-read my post. It is not coming from the battery. It is coming from the metal body of the car. However, even if it was coming directly from the battery terminal, why is that considered wrong and how does that impact the system in a negative manner?



Agreed!!!! Quite honestly I don't remember what the efficiency was. I think it was +/- 50 ohms while resonant on my center frequency. Can you please explain why R or the resistance should not be 50 ohms and rather 37 ohms?

Jesus!!!!! Just when you think you know Jack someone comes along and makes you realize that you only know of Jack.



I don't know how you are getting 10W out of your Baofeng . Which model do you have? I have both the 5R and 82 model and both put out around 3W to 3.5W even though the 82 is suppose to have a little more juice. The only repeaters I have hit without the amp is about 15 air miles away and unfortunately there is no others around here that are within 20 to 50 mile range to test. To me, 60 miles sounds reasonable with about 10W on VHF/UHF. And let me tell you... I know this because I am very knowledgeable. Something tells me that you are not using the factory antenna which by the way, I tested it with the antenna analyser and sure as heck, it's their POS version. Was not resonant anywhere from 2MHz to 175MHz. Maybe on 70cm but not on VHF.

Excuse all the questions. I only have all the radio gear and test equipment. I am trying to learn more about this hobby so I can start using everything properly.



10-4. Copy that.



Huh!!!!! Sounds like he/she is a really cool cat.

But really though....Dickheads can be smart people... On the other hand, you are right they just think they are and my brother-inlaw is the perfect example of that....

F#&*ING DICKHEAD. I promised myself that everytime I thought of him (my brother inlaw), I would use the word dickhead.

You are not doing everything wrong.
While there is a chance that you may smoke your radio due to grounding, it happens so little it's hard to find cases on the net.
Connor has been singing this "you are going to fry your radio" thing for sometime now.
I would just keep your ground as is until you change your install. Almost all ham radios have both "+" and "-" fused, sure wish cb's were that way.

 

[GnG8d]

Rr, Rc and ground loss? Pretty much.

Hardest part is trying to explain it in ways other people can understand.

You're clueless.

 

[Sideways]

To the op, I've done only one 520 mod on a cobra 29, at first had a 3 watt deadkey, 8 watt pep. Played around with cap anf resistor values never could get over 8 watts. Finally took one turn off of l14 coil, didn't think it would make much difference, but hit 20 watts! After tuning, 4 watt carrier, 25-30 watts pep. As for your issue in your mobile, my guess would be voltage drop. With all the electrical parts on cars and trucks these days, they draw a lot of amperage, especially driving down the road. So while sitting in your driveway reving the engine may increase your voltage, the vehicles is not drawing the amperage that it would while under a load. Could try a larger capacity battery, or higher amp alternator. I don't know just a guess, I'm still learning a lot myself. Good luck

 

[M0GVZ]

You're clueless.

Yeah you're right I am. That's why I have a wall of first in country certificates for worldwide contests including a first in world in class. Its why I talk to North and South America from the UK on a daily basis whilst in my car and have no problem doing 9000 miles+ with just 100W when mobile in stark contrast to you where you think you're doing well if you manage to make it across a few states.

 

[binrat]

Yeah you're right I am. That's why I have a wall of first in country certificates for worldwide contests including a first in world in class. Its why I talk to North and South America from the UK on a daily basis whilst in my car and have no problem doing 9000 miles+ with just 100W when mobile in stark contrast to you where you think you're doing well if you manage to make it across a few states.

So what you are saying is that you luck with DX contacts is due to your high quality of install and not skips conditions, is that correct??
I hope all of this on 11 metres as well. Now for 10 metres I have made numerous contact around the world via mobile with 35 watts. Does this make me a better operator, I say no, just lucky with conditions.

 

[CBSlicer]

Guys... trash talk provides no technical assistance at all. Take that somewhere else and pay more attention to the topic. or current questions...

PLEASE?

 

[binrat]

Well, I think Sideways gave some good input on the radio. But from my experience no two radios tune the same. The Wilson 2000 install sounds pretty good, only possible change I can think off is some bonding (grounding), that would help the whole radio systems as well.
Connor did have a good point about your HT / Amp / Antenna. What type of VHF antenna do you have and where is it mounted?

 

[CbRadiosPRONTO]

While we are at the mercy of conditions when skip talking on 10-12 meters, the antenna will make an enormous difference. Power is nothing compared to the antenna. At least that's what they say...me and my Antron 99 wouldn't know.


CbRadiosPRONTO

 

[psycho]

Guys... trash talk provides no technical assistance at all. Take that somewhere else and pay more attention to the topic. or current questions...

PLEASE?

Good thing you just joined the forum to point that out.

 

[GnG8d]

Good thing you just joined the forum to point that out.

He wasn't paying attention either. He missed the part where the OP was being told an antenna tuned to 50+j0 was extremely lossy.

 

[RFEverywhere]

To the op, I've done only one 520 mod on a cobra 29, at first had a 3 watt deadkey, 8 watt pep. Played around with cap anf resistor values never could get over 8 watts. Finally took one turn off of l14 coil, didn't think it would make much difference, but hit 20 watts! After tuning, 4 watt carrier, 25-30 watts pep. As for your issue in your mobile, my guess would be voltage drop. With all the electrical parts on cars and trucks these days, they draw a lot of amperage, especially driving down the road. So while sitting in your driveway reving the engine may increase your voltage, the vehicles is not drawing the amperage that it would while under a load. Could try a larger capacity battery, or higher amp alternator. I don't know just a guess, I'm still learning a lot myself. Good luck

Many thanks. That is the only thing I have not yet tried. Yes.... yes.... I know. Pretty dumb of me to come on here and bitch and moan about how I can't seem to get it working yet, I have failed to follow the all the directions.

Just FYI.... I stopped by the Electronics shop on my way hime and went through their transistor/mosfets section. Grabbed a couple of IRF820, IRF734 and NTE123 to experiment with. I pluged them in the place of the 510 on the Cobra 25 and on each I was able to get about 1.5W out with very small swing. Once I fully figure out and take a turn off of the coil, I shall start playing and figuring out how to bias those Mosfets/transistor. I picked them up for experimental reasons only.