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Gloden Rod 50 (Sig. Engineering)
- Thread starter skirtchaser
- Start date
I do see a difference in the new model which is noted at the top of this thread. I have no experience with this one at all. In the case of this new model I tend to agree with both your and MC remarks about the position I took.
But:
The antenna I was talking about is the older mobile
In comparing the Golden Rod 45 antenna to a SS 1/4 wave whip we noticed very little difference with a varity of local signals when asking for radio signal checks.
During the process DX was rolling and we began to get DX reports stating that the Golden Rod 45 typically showed improved signals over the whip in all cases reported. Several of these DX reports noted that they were using a horizontal beam at the time. We then began to watch the DX signals between three or four other mobile antennas and it was remarkable to us. We wonder why, thus the idea about the physical nature of the antenna was born. We just figured we were seeing some horizontal RF with the top portion of the GR45 that was absent in the others. For us, the claim by SE was verified by our results.
I guess Mopar could give us his own report what he has found under similar circumstances if he noticed anything. The test is not hard to conduct, except that at present DX is limited to non-existant.
This was not the end of such comparing, testing, and verification of such differences with vertical antennas that have substaintail physical horizontal surfaces in their mix, but these were my observations.
But:
The antenna I was talking about is the older mobile
In comparing the Golden Rod 45 antenna to a SS 1/4 wave whip we noticed very little difference with a varity of local signals when asking for radio signal checks.
During the process DX was rolling and we began to get DX reports stating that the Golden Rod 45 typically showed improved signals over the whip in all cases reported. Several of these DX reports noted that they were using a horizontal beam at the time. We then began to watch the DX signals between three or four other mobile antennas and it was remarkable to us. We wonder why, thus the idea about the physical nature of the antenna was born. We just figured we were seeing some horizontal RF with the top portion of the GR45 that was absent in the others. For us, the claim by SE was verified by our results.
I guess Mopar could give us his own report what he has found under similar circumstances if he noticed anything. The test is not hard to conduct, except that at present DX is limited to non-existant.
This was not the end of such comparing, testing, and verification of such differences with vertical antennas that have substaintail physical horizontal surfaces in their mix, but these were my observations.
The goldenrod 45 does respond to hoz. signal.Tested this antenna with 2 locals.1 with a 7 element flat side and the other with a 4 element flat side.Both had a99 to switch to compare vertical side.I was about 15 miles away from both stations.I could talk back to both stations flat side and vertical.Install my Wilson 1000 and could not hear them on flat side but no problem on the vertical side.I know this was a simple test but it worked.I still have the antenna but its a little ugly to run on the car.Wife says it looks like something you hang your coat. 
I wish that I could give you guys a decent report about the antenna. But unfortunately I didn't get to test the antenna very well. I had to give it back before I got a chance to really put it side by side with other antennas. For the little time I had it, it really seemed to work well.
One other thing to ponder. There is quite a bit of wire in the top of that antenna. Somewhere around 80+ inches of wire horizontal in an antenna that is only 55 1/2 inches tall (I think newer ones than the one that I had are 51 inches?). In the newer ones, I have been told the capacitance hat is even bigger than the one I had. I didn't measure the wire precisely, I can only tell you the "loops" are 18.5" by 7" each.
Take care,
Mopar
One other thing to ponder. There is quite a bit of wire in the top of that antenna. Somewhere around 80+ inches of wire horizontal in an antenna that is only 55 1/2 inches tall (I think newer ones than the one that I had are 51 inches?). In the newer ones, I have been told the capacitance hat is even bigger than the one I had. I didn't measure the wire precisely, I can only tell you the "loops" are 18.5" by 7" each.
Take care,
Mopar
Thanks 1200 for pitching in with your real world test.
That is more or less what we were doing without thinking about it at the time. Had we not noticed the DX response back then we would never have thought about such a scheme for a test.
With DX you never know what the RX/TX polarity of a signal will be at any point in time, but when you switch ver/hor you can observe what seems to be working for the moment.
Since this experience I refined the test to do it with more control and that is exactally as you did in your test.
I also find similar results when comparing the Astro Plane to a more traditional vertical. When working an AP against a fixed station horizontal beam locally I notice it respond much better than the A99 we used to test. I noted that the difference was striking and the response was also evident at closer ranges, 3-5 miles.
Thanks again 1200, if you get a chance to re-confirm your test, let us know.
That is more or less what we were doing without thinking about it at the time. Had we not noticed the DX response back then we would never have thought about such a scheme for a test.
With DX you never know what the RX/TX polarity of a signal will be at any point in time, but when you switch ver/hor you can observe what seems to be working for the moment.
Since this experience I refined the test to do it with more control and that is exactally as you did in your test.
I also find similar results when comparing the Astro Plane to a more traditional vertical. When working an AP against a fixed station horizontal beam locally I notice it respond much better than the A99 we used to test. I noted that the difference was striking and the response was also evident at closer ranges, 3-5 miles.
Thanks again 1200, if you get a chance to re-confirm your test, let us know.
"i am sure freecell had something to say about the goldenrod-45 a while back but i cannot find it........"
i think this is what you were looking for........
http://forum.worldwidedx.com/viewtopic.php?p=40283&highlight=gr45#40283
A short, vertical antenna suffers from several disadvantages, low base resistance, high values of reactance and excessive high-angle radiation. top-loading in its several forms is not only an attempt to contribute to the electrical length in an effort to more closely approximate a full 1/4 wavelength but to also mitigate both radiation resistance, input impedance and current distribution, to balance those values to produce more efficient radiation of the em wave and prevent excessive I2R losses wasting transmitter energy in the form of heat. the gain figure associated with the GR45 @ 4.75 Dbi is more believable than most, and in case some of you missed it IS compared to the "unity" gain produced by the isotropic source, Db = decibels, i = isotropic. as 351 alluded to in his post, this antenna performs at its best when used in environments such as hilltop vantage point terrain and also in wide-open unobstructed areas that are mostly rural in nature as the top-hat also serves to eliminate large amounts of wasted upward radiation only useful in more suburban and urban environments or for high angle, short hop sky wave propagation. with the GR45 operating in the type of terrain that it was designed for, you will be hard pressed to find anything else in a 4'3" package handling 12KW of power that will perform as well. and with one last reference to the quoted gain, 4.75 Dbi, 2.64 Dbd, try constructing a 1/2 wave dipole at the same feedpoint height (if you can) as a comparable installation of a GR45 and see for yourself how quickly the ground losses at that height above ground just eats up any gain that might have been produced by the dipole because of its close proximity to ground and you'll get a glimpse of just exactly what some of the other functional attrubutes of capacitive top-hat loading actually contribute to an antenna design such as this.
so there are at least 5 quantitative values that top-loading attempts to balance and affect in a favorable manner, radiation resistance, impedance, I2R/ground losses, electrical length and elimination of wasted skywave radiation in an attempt to increase the efficiency and the gain of a physically shortened 1/4 wave radiator. now it's no longer a mystery.
i have always contended that there was a significant horizontal component present in the far-field radiation pattern of the GR45 and have never doubted that the claims made by SE were anything but honest observation. even the placement of the loading coil directly underneath the top hat would seem to defy conventional logic in antenna designs such as this but that's okay because it gives me something else to think about and study.
on the other hand it's always nice to be vindicated.
i think this is what you were looking for........
http://forum.worldwidedx.com/viewtopic.php?p=40283&highlight=gr45#40283
A short, vertical antenna suffers from several disadvantages, low base resistance, high values of reactance and excessive high-angle radiation. top-loading in its several forms is not only an attempt to contribute to the electrical length in an effort to more closely approximate a full 1/4 wavelength but to also mitigate both radiation resistance, input impedance and current distribution, to balance those values to produce more efficient radiation of the em wave and prevent excessive I2R losses wasting transmitter energy in the form of heat. the gain figure associated with the GR45 @ 4.75 Dbi is more believable than most, and in case some of you missed it IS compared to the "unity" gain produced by the isotropic source, Db = decibels, i = isotropic. as 351 alluded to in his post, this antenna performs at its best when used in environments such as hilltop vantage point terrain and also in wide-open unobstructed areas that are mostly rural in nature as the top-hat also serves to eliminate large amounts of wasted upward radiation only useful in more suburban and urban environments or for high angle, short hop sky wave propagation. with the GR45 operating in the type of terrain that it was designed for, you will be hard pressed to find anything else in a 4'3" package handling 12KW of power that will perform as well. and with one last reference to the quoted gain, 4.75 Dbi, 2.64 Dbd, try constructing a 1/2 wave dipole at the same feedpoint height (if you can) as a comparable installation of a GR45 and see for yourself how quickly the ground losses at that height above ground just eats up any gain that might have been produced by the dipole because of its close proximity to ground and you'll get a glimpse of just exactly what some of the other functional attrubutes of capacitive top-hat loading actually contribute to an antenna design such as this.
so there are at least 5 quantitative values that top-loading attempts to balance and affect in a favorable manner, radiation resistance, impedance, I2R/ground losses, electrical length and elimination of wasted skywave radiation in an attempt to increase the efficiency and the gain of a physically shortened 1/4 wave radiator. now it's no longer a mystery.
i have always contended that there was a significant horizontal component present in the far-field radiation pattern of the GR45 and have never doubted that the claims made by SE were anything but honest observation. even the placement of the loading coil directly underneath the top hat would seem to defy conventional logic in antenna designs such as this but that's okay because it gives me something else to think about and study.
on the other hand it's always nice to be vindicated.
freecell i could join my 22" and 27" shaft p10k's add the spacer from the dual coil then screw a bolt with 2 large washers bent to clamp the tophat,
that would make something like the gr45 with just about the same length shaft but fatter and the same space between tophat and coil,
how critical are the coil and tophat dimentions??
the gr45 has 8.5turns just over 1.5" diameter while the 10k is 6.5 turns of fatter tube at just over 2" diameter, with a similar winding length,
if the coil is too small can a larger hat compensate and do the same overall job or is there a relationship between coil and hat that is optimal??,
something better for dx than the stock 10k when stationary on high ground in a field would be great
that would make something like the gr45 with just about the same length shaft but fatter and the same space between tophat and coil,
how critical are the coil and tophat dimentions??
the gr45 has 8.5turns just over 1.5" diameter while the 10k is 6.5 turns of fatter tube at just over 2" diameter, with a similar winding length,
if the coil is too small can a larger hat compensate and do the same overall job or is there a relationship between coil and hat that is optimal??,
something better for dx than the stock 10k when stationary on high ground in a field would be great
bob85,
Yes, the relationship between coil, capacitive hat, and mast length and diameter are all critical, or at least do make a difference in the frequency the antenna is used on. IN other words, the whole mess is a tuned 'circuit'. Changing any one part of that circuit will change it's relationship in terms of resonance to a particular frequency or band of frequencies.
A coil's inductance and inductance reactance is determined by that coil's length, diameter, turns spacing, size of the conductor used to make the coil, and whatever is inside the circumference of that coil (air, plastic, dead bugs, etc.).
A capacity hat's reactance is determined by the total area of the hat, what size the conductor that makes it is, it's 'nearness' to the rest of the antenna and ground, and probably it's color!
Any of those 'parts' can be changed to change the antenna's resonance. How easy and how much it/they have to be changed is one of those huge 'depends' sort of things, and why they all aren't normally used to do the tuning. Sometimes, it just isn't worth the effort to change something for the difference it will make, another one of 'those' thingys.
Is it possible to modify a loaded antenna to perform just as well as an unloaded antenna designed for the same frequency? No. You can get real close, but it just ain't gonna be worth the effort in most cases. In very special cases? You bet, but that just depends on the case and the total amount of effort required, right?
- 'Doc
Yes, the relationship between coil, capacitive hat, and mast length and diameter are all critical, or at least do make a difference in the frequency the antenna is used on. IN other words, the whole mess is a tuned 'circuit'. Changing any one part of that circuit will change it's relationship in terms of resonance to a particular frequency or band of frequencies.
A coil's inductance and inductance reactance is determined by that coil's length, diameter, turns spacing, size of the conductor used to make the coil, and whatever is inside the circumference of that coil (air, plastic, dead bugs, etc.).
A capacity hat's reactance is determined by the total area of the hat, what size the conductor that makes it is, it's 'nearness' to the rest of the antenna and ground, and probably it's color!
Any of those 'parts' can be changed to change the antenna's resonance. How easy and how much it/they have to be changed is one of those huge 'depends' sort of things, and why they all aren't normally used to do the tuning. Sometimes, it just isn't worth the effort to change something for the difference it will make, another one of 'those' thingys.
Is it possible to modify a loaded antenna to perform just as well as an unloaded antenna designed for the same frequency? No. You can get real close, but it just ain't gonna be worth the effort in most cases. In very special cases? You bet, but that just depends on the case and the total amount of effort required, right?
- 'Doc
you can do that bob but you don't end up with the GR45, what you end up with is a lossy, loaded dipole and as i stated previously if placed at the same feedpoint height above ground as the GR45 would operate miserably.
and yes, a shortened vertical can and does function as well and in some instances even better than it's physically full size counterparts for a number of reasons mentioned previously, most of which seem to have eluded some of us. the total physical length of the GR45 is not limited only to its vertical height measurement of 51" (the top hat constitutes additional physical length) and one of the requirements of a highly efficient shortened vertical is that its total physical length constitute the majority of the overall length of its full size quarter wave counterpart. signal strength from the GR45 when compared to the 1/4 wave SS reveals no difference at all or ever so slightly favoring the latter of the two antennas particularly when tested in something other than flat or on mountain top terrain while when working with dx signals the 1/4 wave SS is no match for the GR45 with regard to simple gain based solely on the concentration of the radiated signal into the lower radiation angles and the 1/4 wave SS offers no help in handling polarization rotation of dx signals and the attendant fading that accompanies them. the 1/4 wave SS will react the same way that the wilson antenna did that was mentioned previously in that it will not respond favorably to horizontally polarized signals.
with the size of vehicles becoming smaller and the introduction of non metal body components including fiberglas and plastic the input impedance of antennas used on these vehicles continues to shrink simply because there isn't enough metal in long enough runs in any direction from any mounting location to allow full size antennas to be properly "mirrored" and thus efficiency suffers. the fact of the matter is that shortened vertical antennas that are properly designed can overcome these limitations to a great degree by virtue of their physically smaller footprints while decreasing I2R ground losses by raising the high current points further up the length of the antenna and simultaneously provide improved communications out to a much further extended horizon as a result. while some of you may not be able to explain exactly what is happening you are seeing results similar to those i mentioned previously. now you have some insight into the why.
some of you here experienced the same thing using the popular open air coil loaded antennas some time back when you added shaft length to place the loading inductors at higher vantage points and many of you reported undeniable improvements in both transmitting and receiving distances and even improvements in matching values as a result. in every loaded antenna there is a point where the current reaches a maximum value as the resultant generated electric field reaches its zenith and the collapsing electric field leaves in its wake a newly generated magnetic field formed by the ensuing voltages. as a general rule, the higher up the length of the antenna that this transition takes place (all other things being equal) the further the antenna "talks" and "hears".
and yes, a shortened vertical can and does function as well and in some instances even better than it's physically full size counterparts for a number of reasons mentioned previously, most of which seem to have eluded some of us. the total physical length of the GR45 is not limited only to its vertical height measurement of 51" (the top hat constitutes additional physical length) and one of the requirements of a highly efficient shortened vertical is that its total physical length constitute the majority of the overall length of its full size quarter wave counterpart. signal strength from the GR45 when compared to the 1/4 wave SS reveals no difference at all or ever so slightly favoring the latter of the two antennas particularly when tested in something other than flat or on mountain top terrain while when working with dx signals the 1/4 wave SS is no match for the GR45 with regard to simple gain based solely on the concentration of the radiated signal into the lower radiation angles and the 1/4 wave SS offers no help in handling polarization rotation of dx signals and the attendant fading that accompanies them. the 1/4 wave SS will react the same way that the wilson antenna did that was mentioned previously in that it will not respond favorably to horizontally polarized signals.
with the size of vehicles becoming smaller and the introduction of non metal body components including fiberglas and plastic the input impedance of antennas used on these vehicles continues to shrink simply because there isn't enough metal in long enough runs in any direction from any mounting location to allow full size antennas to be properly "mirrored" and thus efficiency suffers. the fact of the matter is that shortened vertical antennas that are properly designed can overcome these limitations to a great degree by virtue of their physically smaller footprints while decreasing I2R ground losses by raising the high current points further up the length of the antenna and simultaneously provide improved communications out to a much further extended horizon as a result. while some of you may not be able to explain exactly what is happening you are seeing results similar to those i mentioned previously. now you have some insight into the why.
some of you here experienced the same thing using the popular open air coil loaded antennas some time back when you added shaft length to place the loading inductors at higher vantage points and many of you reported undeniable improvements in both transmitting and receiving distances and even improvements in matching values as a result. in every loaded antenna there is a point where the current reaches a maximum value as the resultant generated electric field reaches its zenith and the collapsing electric field leaves in its wake a newly generated magnetic field formed by the ensuing voltages. as a general rule, the higher up the length of the antenna that this transition takes place (all other things being equal) the further the antenna "talks" and "hears".
Interesting idea
Anyone do any Field strength testing against the 45 as a comparison ? I wonder how the field strength would compare to base loaded mobile.
I think the best mobile antenna thus far has been the continuous wound variety for one seeking the holy grail of mobile antennas this would be a starting point.
next being a Bazooka style antenna. Why has no one mounted and displayed this american original ? Let me say when you see F.S. from one of these DX killers you know its putting out what goes in.
Anyone do any Field strength testing against the 45 as a comparison ? I wonder how the field strength would compare to base loaded mobile.
I think the best mobile antenna thus far has been the continuous wound variety for one seeking the holy grail of mobile antennas this would be a starting point.
next being a Bazooka style antenna. Why has no one mounted and displayed this american original ? Let me say when you see F.S. from one of these DX killers you know its putting out what goes in.
How it works probably doesn't matter since you can't even get Signal Engineering to respond to an email much less sell you an antenna. I'm also surprised it's been marketed for off road use. How long before a branch gets caught in the top hat and mangles that I wonder?
use to sell there
antennas when i had my shop back in the 80s and 90s...didnt know they still where in bussiness...have to check that out,ran a thunder 8b for years,realy liked it...73 de JW
antennas when i had my shop back in the 80s and 90s...didnt know they still where in bussiness...have to check that out,ran a thunder 8b for years,realy liked it...73 de JW
B
BOOTY MONSTER
Guest
SW, try this website address for the contact info. I haven't heard a thing about this new business that advertises the SE antennas, but it's worth a try.
GR45′s Recent Testimonials « LIGHTNING's "True CB Quad" Antennas
Here are some models I did of the GR45 based on the dimensions that Bob gave us in this thread. I also did a model with the top element a full 1/4 wavelength for comparing to the GR45 to specs, and the same antenna tuned a little better to resonance. The models are over Real Earth, using the 4 x 108" slanted radials at 45* degrees.
I also included an overlay for all three models.
Bob, if you still have those dimensions for the GR45, maybe you could help me understand the coil a little better. Just let me know, and I will ask you for some specifics, and if you still have same, it will help get the model a bit closer. The numbers I got off of your post ended up to short, so I tuned it a little by making it about 7" longer. Maybe another coil would fix it.
I don't see enough difference between these models to make any claims, one way or another. The patterns are one on top of the other.
View attachment Golden Rod 45.pdf
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