IMAX2000 no GPK vs 1/2 wave Silver Rod

[Needle Bender]

Crazy D. with all due respect, I have 35 years in communications and I have never seen any transmission line, be it ladder line, coax, hard line, or even fiber optic than can INCREASE SIGNAL strength of an RF signal.

The claims of your heliax greatly improving tx and rx over lmr400 at HF frequency would need to have some very expensive, sensitive test equipment to see any difference in receive or transmit.

A simple S meter on a CB would not even show a needle width of difference.

Post a video or something to substantiate your claim.

Not saying you are not telling the truth, just looking at specifications of cable loss at HF freq for the two transmission cables you are using.

Now if it was UHF MAYBE there could be that big a difference.

Unless he's a couple hundred yards from the antenna, we had hill property and to get to the ridge req'd 850' of coax. That's where I learned the cold hard truth about manufacturer's specs - they don't lie. 120w out the back of the Yaesu read 6/10w at the antenna, that's POINT 6 WATTS, 600 milliwatts was all that made it to the ridge using 2.7dB loss per 100' Mini-RG8.
That was 1984, how I wish I would've known about balanced line back then!

 

[wavrider]

75 feet of transmission line was in he post, at 75 feet could use rg8x and not have any noticeable loss.

http://www.arrg.us/pages/Loss-Calc.htm

lmr4oo at 75 feet has around 11 watts loss , 100w power 89 watts get to the antenna.

IF hard line is loss less ( which it is not) then lets say 100 watts makes it to the antenna, I know of no amateur or cb receiver sensitive enough to display the difference between 100 watts and 89 watts??

 

[Crazy_D]

Crazy D. with all due respect, I have 35 years in communications and I have never seen any transmission line, be it ladder line, coax, hard line, or even fiber optic than can INCREASE SIGNAL strength of an RF signal.

The claims of your heliax greatly improving tx and rx over lmr400 at HF frequency would need to have some very expensive, sensitive test equipment to see any difference in receive or transmit.

A simple S meter on a CB would not even show a needle width of difference.

Post a video or something to substantiate your claim.

Not saying you are not telling the truth, just looking at specifications of cable loss at HF freq for the two transmission cables you are using.

Now if it was UHF MAYBE there could be that big a difference.

I have 30 years into all of this myself, and on hf/vhf/uhf. I have seen nice improvements and I could hear stations that NO ONE else in my entire local city area of over 100 other operators could hear, it was AMAZING! Mind you this was back in 2008-2009 on these specific coax tests (my antenna tests started in 2005), I sold my mr coily and heliax back in 2010 when I moved to a townhouse and now use a maco ba-1. I just catched this thread as I was playing around with a imax 2K and silver rod a couple weeks ago late at night, they are both sitting here in the corner looking at me.

Let me give you some facts of my past install, I looked up my stuff as I still have that LMR400 piece laying around and it was a 100foot, not 75feet. My original feed line was a 100 foot of LMR-400 (N connector at antenna, PL-259 inside), I replace it with 70 feet, not 75feet (which was the original length from my receipt), sorry I wasn't thinking too indepth on my prior posting (I remembered I wanted it short as possible and I used that 5 foot piece I cut off which was excess, as a jumper for a high power bird coaxial resistor that I used with a "spare/backup" 3cx3000 amp to heat a room, literally) of Heliax LDF5-50A 7/8", which was terminated to a 7/16" DIN at the mr coily antenna, and went straight to a 7/8" EIA Flange at the amplifier. I sold the heliax with the antenna, I remember the guy was bummed it wasn't 75feet because it just did not reach for his install, remember I sold this stuff like 5-6 years ago now. When I did the heliax change, I had also changed the antenna out to a brand new mr coily as I ordered one with the higher power, less lossy 7/16" DIN. I gave the other antenna to a buddy of mine for labor trade.

Ok, its time to do the numbers of my past setup, now you will see the differences and the gains.

~At 27.205mhz (center of band), 100 feet of LMR400 has 0.635dB loss. 100watts in, 86.397 watts out (not counting any connector losses).
~At 27.205mhz (center of band), 70 feet of LDF5-50A has 0.186dB loss, that is 0.449dB better than the LMR400. I was also getting 97watts out of the feedline with 100 watt in, a difference of 11 watts, or 11%. But when I start cranking up the power, the numbers start getting more staggering comparing these two feedlines! Lets take it up to 1500w.
~27.205 LMR-400 100' 1500 watts in, 1295watts out. Loss of 205 watts!
~27.205 LDF5-50A 70' 1500 watts in, 1437watts out, loss of 63 watts! 142 less watts wasted as heat and out onto the air in my past setup.

And for those strict ham people who are going crazy with me typing in, 1500watts on 27mhz, I ran the numbers on 28.400 at 1500w and its only a couple watts between the two compared to the 11m numbers, pretty much the same.

As you can see with all the better efficiency of the heliax compared to the LMR400 (and I know there was a 30 foot difference, I was super anal back then about loss), and the connector loss differences that this translates to better receive and transmit, even at 27mhz CB frequencies. Now, I have also done the swap at 144mhz for 2M ssb from LMR400 to heliax 7/8 and that even more of a difference but that was only done for a quick hookup test I did not run it like that for more than a day because of the weight of the feedline on the M2 2M12 beam I was using.

Regardless of my past setup information above, if you had 100' of RG8X, 100' of LMR400 or 100' of LDF5-50A, you will see a higher signal on the heliax. BTW, 100watts into 100' of RG8X is a measely 67 watts out, 86 watts out on the LMR400, and 95 watts out on the heliax 7/8", all lengths equal. 9% improvement switching over to hardline 7/8". The probagation velocity factor is also greater by 5% on the 7/8" vs LMR400. Run all 3 lengths and do only a RECEIVE test, no transmit, and you will come back with a good (rg8x), better (lmr400), and best (ldf5-50a). I have swapped out so many runs of 100 foot of rg8x to belden 9913 or lmr 400 (or clone cable) over the years on various antennas and I have seen rx/tx improvements at 27mhz by just swapping coaxes out. If I remember right, I think it was like a 1 to 2 s-unit difference, on both rx and tx. I remember the first time I did it about 23 years ago on a antron 99, I went from tandy rg8x to belden 9913 and you will see the difference.

Another improvement that my distant station saw was when I treated all the connections with a advanced and expensive silver contact paste I use for other hobbies, it was more prevalent on VHF and more so uhf, I gained typically 1/2 to 1 sunit (or in some cases, a extra signal "block" on someones meter) by simply pasting my connections, I have shown so many guys who thought it would do nothing and totally fooled them on the air (this was on VHF and UHF). I noticed far less gains at HF/CB like a quarter of a s-unit or so, small needle amount.

 

[The DB]

I have 30 years into all of this myself

On the number of years doing this, I know you weren't the first to post theirs, so this part is more of a general response to everybody... I've been doing this for 25 years, and I've learned more in each of the last five years than I've learned in all of the first 20 years combined. I also know people that have been doing this for 50 plus years that I wouldn't let near an antenna. Giving a number of years impresses only those that don't know what they are doing, and really says nothing about what you do and don't know. You wouldn't believe how many times I found myself being amazed at the basic concepts that various people that have been doing this as long or longer than I clearly didn't understand...

I was just amazed again at someone with more claimed years than me blowing a small change out of proportion. The changes in numbers you are reporting on will make absolutely no noticeable difference. If you wanted to see a difference you would notice, you would have to increase the amount of those changes significantly. An s-meter, unless it was hopelessly bad, and by this I mean far worse than exists even in most cheap CB radios, would not show any difference between these posted numbers. A person hearing your voice over the radio will also be unable to tell the difference.

Also there is the phrase "has to go somewhere". Unless blocked, redirected, or absorbed by something, radio waves will continue on into infinity, although due to their nature they will continually get weaker as they continue to travel. The additional power isn't going anywhere the radio waves are not already going, it is just that said waves are slightly stronger at any given point. How quickly said signals get weaker is known, and for any noticeable change in said signal you really need closer to a 3 dB increase or decrease. That 0.449 dB that you are raving about is simply no where near enough to be noticed. Sorry, but that is just how it is.

More likely, if you noticed an actual difference going from LMR-400 to heliax on the CB band, the source was a problem with your LMR-400 was likely bad. There is also potentially a human perception problem. People get this nice fancy piece of equipment and want to believe that it is working better than an older piece of equipment even if it isn't, and this actually causes them to think they actually perceive a difference. I've unfortunately seen this happened more times than I can count.

Is it possible that your setup has a quieter receive than others around you. Yes, I have no reason to not believe that point. Often, the biggest difference between antenna systems is the amount of noise one picks up compared to another. With a quieter antenna system you can hear the weaker signals that is drowned out by noise in other not as quiet antenna systems. But even this can depend on why one antenna is quieter than another. Not all causes of a quiet receive are good...

I am curious, why would you think we would bat an eye at 1500 watts of output power? I know of people around here that run two to three times that in their vehicles on the CB band, although, they don't normally turn it up that high unless they need to. I know plenty of hams that run 1500 watts as well. I guess I don't get why people would see that 1500 watt figure as crazy... That being said, I would be more impressed if you were able to accomplish the same feats with a five watt system. Running lots of power does not impress me, running less power and still making contacts and things like still getting through pileups quicker than people running much more power is what impresses me. In my experience, output power is not a substitute for operator skills.

NOTE, my references here is strictly related to the CB band. I would expect there to be more of a difference on VHF/UHF bands. I haven't looked up the numbers, but in those cases there might be enough of a difference to notice. That being said, most of the post I am responding to is referring to the CB band, and VHF/UHF is only mentioned in a much smaller part of said message.


The DB

 

[Crazy_D]

you guys are only seeing and talking about "half" the picture here (TX), its totally not about the power number "specs" here like 86 to 97 for example, when in reality it is about sensitivity from outside antenna signals getting from the air to your receiver. It needs to travel through your antenna, connectors and coax and then up to your rig. Plainly put, your receiver will see a higher signal voltage coming in through the lower loss heliax cable (especially the 7/8") and thus your will receive and transmit a higher signal over the lossier cable. I didnt think I was going to see the difference I did when I did the swap, the signal my station put out was and is legendary in this area, people are still talking about a couple historic keydowns I did back 7 years ago. No one for 20 miles could talk, I clean hammered people even when mobiles were less than a mile away. I miss those total control days where no one could ever key on you and you keyed on base stations that were a mile or less apart.

 

[Crazy_D]

O

NOTE, my references here is strictly related to the CB band. I would expect there to be more of a difference on VHF/UHF bands. I haven't looked up the numbers, but in those cases there might be enough of a difference to notice. That being said, most of the post I am responding to is referring to the CB band, and VHF/UHF is only mentioned in a much smaller part of said message.


The DB

I did a number of test on vhf/uhf with LDF4-50A (half inch)and I noticed a improvement for sure over the LMR400, I cant exactly remember the improvements but they were more substantial that the much smaller improvements I seen at CB freqs. This was all done over 10 years ago. I was running a comet GP9N base antenna and had swapped out lmr400 to heliax ldf4-50a (my first heliax) and that was a improvement, but I cannot give any numbers because its been too many years to remember. However, I do distinctly remember that when I swapped out the pigtail connector on my Yaesu FT-100D, on the VHF/UHF port, to a N connector pigtail, I gained a complete signal block (dont know how that is relatively scaled) on every radio that copied me (this was on FM so no one was using a radio with a needle meter). I was not into VHF/UHF SSB at that time, only FM as I had a crew of guys on 2m or 70cm FM. I also noticed that I received another block on a distant UHF repeater and I could hear others slightly better, that was another eye opener, replacing a SO-239 for vhh/uhf to N connector, doing that and silver pasting your connections it was stunning, you guys HAVE to do this if you run a radio with this type of non-optimal connection on the output. I also silver paste all my HT antennas connections and I get another small single "block" of extra signal on all reports I have had on simplex, that extra signal "block" was in reference on a yaesu FT-8900R radio that was being used by two of the guys copying me. It works even better if you are using 2-3 connectors to make one connection like you might have to do on a HT to a external antenna. I want to mention that I had also silver pasted the newer mr coily ground plane (the entire antenna connections, everywhere, I took it apart at the coil and did those too). That HAD to help out in the total equation of things as that is only aluminum which is not a good conductor so silver pasting made it in effect a psuedo solder connection at each point pretty much, but since I did that all at once I was never able to do any A/B'ing like I had wanted too (plus it was going to take up too much time because the silver paste has a break in period that is wild since it is cryo treated).

btw, it really doesnt matter how long one has been doing this, one could be doing it for 50 years and never dig too deep, but a guy could be doing it for only 5 years and dug very deep into the subject and schools a elder who thinks he knows everything on theory when the other guy has more compacted hands on experience, i would take that over the old man trying to tell me what to do (and this is how I have grown up, NOT listening to others and doing things on my own and finding my own conclusions).

 

[Crazy_D]

One thing I never got a chance to getting around too back in 2009 before I took every thing down and moved, was inquiring with Andrews or Commscope if they could make a custom length of hardline made with complete pure silver conductors (not silver plated!) instead of copper (or atleast the center conductor...). I knew it was going to be expensive but wanted to be a guinea pig as silver is 5% better conductor than copper and I wanted to see what was going to happen to the outcome at hf/vhf/uhf. Hmmmm....

 

[The DB]

Going up in frequency will increase the losses for a given piece of feedline. Higher frequencies are more sensitive, so as I mentioned above, it is far more likely to make a noticeable difference.

From personal experience, SO-239 has minimal losses as measured by my AIM4170c VNA through 180 MHz, the highest frequency it can measure. It takes a signal two passes over one of these connections to barely measure 0.01 dB loss, which is the smallest amount that the device can measure, which leaves to much room for my taste for a margin of error, so to get an accurate reading I had to add in more SO-239 connections. In the end, using nothing but multiple SO-239 connections I was able to calculate close to a 0.003 dB loss per connection for a single pass of a measured RF signal at 180 MHz.

When it comes to feed line such as coax, heliax, and hard line I think you misunderstand how it functions. Most of the signal does not travel within the conductors, but in the space between the conductors. Changing the dielectric material is how you would change the properties of this type of feedline as that is what affects things like velocity factor and losses the most. I'm not saying the internal wire and the shielding won't have any effect on said factors, but the effect it has is very minimal.

I've actually seen a homemade "hardline" if you will made out of copper tubing before. A friend used two different sizes of copper water pipes, and used something every so often to maintain their separation between the inside and outside tubes. He made a piece the length of about 100 feet and we used my VNA to test it. It had a velocity factor of very close to 1, and essentially no measurable losses. To measure losses accurately we determined we would need a longer piece, which was not practical. This was a straight piece so I'm not sure how bending would work, he never got around to making such a piece. I had thought about trying to make such a piece but never got around to it myself. It had an impedance in the upper 40's, as I recall. Maybe 48 ohms? I can't remember the exact figure, but it was close enough to be use able...

I've also seen video where commercial broadcast stations have essentially a similar setup of two copper tubes with the outside being 3 inches wide or so (I think, sizing estimate from looking at said picture). These tubes also have a specific piece that attaches for bends in said feed line giving access to 45 and 90 degree bends. Like the one my friend built, it has an air core with separators every so far inside.


The DB

 

[RadioDaze2.0]

On the number of years doing this, I know you weren't the first to post theirs, so this part is more of a general response to everybody... I've been doing this for 25 years, and I've learned more in each of the last five years than I've learned in all of the first 20 years combined. I also know people that have been doing this for 50 plus years that I wouldn't let near an antenna. Giving a number of years impresses only those that don't know what they are doing, and really says nothing about what you do and don't know. You wouldn't believe how many times I found myself being amazed at the basic concepts that various people that have been doing this as long or longer than I clearly didn't understand...

I was just amazed again at someone with more claimed years than me blowing a small change out of proportion. The changes in numbers you are reporting on will make absolutely no noticeable difference. If you wanted to see a difference you would notice, you would have to increase the amount of those changes significantly. An s-meter, unless it was hopelessly bad, and by this I mean far worse than exists even in most cheap CB radios, would not show any difference between these posted numbers. A person hearing your voice over the radio will also be unable to tell the difference.

Also there is the phrase "has to go somewhere". Unless blocked, redirected, or absorbed by something, radio waves will continue on into infinity, although due to their nature they will continually get weaker as they continue to travel. The additional power isn't going anywhere the radio waves are not already going, it is just that said waves are slightly stronger at any given point. How quickly said signals get weaker is known, and for any noticeable change in said signal you really need closer to a 3 dB increase or decrease. That 0.449 dB that you are raving about is simply no where near enough to be noticed. Sorry, but that is just how it is.

More likely, if you noticed an actual difference going from LMR-400 to heliax on the CB band, the source was a problem with your LMR-400 was likely bad. There is also potentially a human perception problem. People get this nice fancy piece of equipment and want to believe that it is working better than an older piece of equipment even if it isn't, and this actually causes them to think they actually perceive a difference. I've unfortunately seen this happened more times than I can count.

Is it possible that your setup has a quieter receive than others around you. Yes, I have no reason to not believe that point. Often, the biggest difference between antenna systems is the amount of noise one picks up compared to another. With a quieter antenna system you can hear the weaker signals that is drowned out by noise in other not as quiet antenna systems. But even this can depend on why one antenna is quieter than another. Not all causes of a quiet receive are good...

I am curious, why would you think we would bat an eye at 1500 watts of output power? I know of people around here that run two to three times that in their vehicles on the CB band, although, they don't normally turn it up that high unless they need to. I know plenty of hams that run 1500 watts as well. I guess I don't get why people would see that 1500 watt figure as crazy... That being said, I would be more impressed if you were able to accomplish the same feats with a five watt system. Running lots of power does not impress me, running less power and still making contacts and things like still getting through pileups quicker than people running much more power is what impresses me. In my experience, output power is not a substitute for operator skills.

NOTE, my references here is strictly related to the CB band. I would expect there to be more of a difference on VHF/UHF bands. I haven't looked up the numbers, but in those cases there might be enough of a difference to notice. That being said, most of the post I am responding to is referring to the CB band, and VHF/UHF is only mentioned in a much smaller part of said message.


The DB

Great post and I am afraid I just have to blow my trumpet a bit : )

170W PEP here approximated. 13,300 miles achieved with a Gain Master to Wakatane New Zealand from the UK. (long path !)

A bit of luck and a bit of will/determination/planning. I got in before the beam users because he was coming in long path (A rare advantage from an omnidirectional). I called once and QSY'd and boom I had Rene (41SD101) S1-S3 coming back to me. I probably would never have cut through once the beam ops found him. No power mic no $2,000 radio. Alinco DR135-UK ($190.00 worth of Chinese radio)

I was over the moon (well... a bit more than 1/2 way round the world at least). To be fair he operates a beam but nonetheless that is quite some contact for a vertical omni antenna on 11m. I have since spoke to some hams and they say NZ is rare on a beam with some experienced ops never having spoke to NZ from the UK in years of operation.

A bit of luck and a bit of effort. I was out when I needed to be (09:00AM) with the right setup for the job. I saw the day before skip was ok down into Australia and I thought no way am I going out without the Gain Master at 7.5M high to get that radiation lobe as low as I practically can for a static mobile setup.

What also helped is that European skip conditions were not good. This allowed me to hear better. The stars aligned.

My experiences and efforts paid off.

Sorry to have gone a bit off topic there but it does tie in nicely with the point made.