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Hustler mobile antenna
I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz.
Although it was designed as a mobile I want to use it as a portable, can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire |
I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz.
Can anybody tell me the length of the counterpoise needed for this model? A 1/4 wave counterpoise would be about 65 feet or 20 meters. Mobile antennas use the vehicle body as a counterpoise. Your 65' wire or a vehicle used as a counterpoise will not produce very good results, because the efficiency of the short radiator is only a couple of percent. As an option, a really good performing portable 80m antenna that I have used many times is an inverted vee supported by one of those 33' fiberglass poles. It is fed with 450 ohm line and a tuner. The vee is 50' (15 meters) per leg. You will need about 80'-90' to spread the vee. That's a lot of space, but you will need 65' for the counterpoise for the Hustler. It will beat the Hustler-counterpoise idea significantly, and you can QSY all over the band. With a Hustler you have a narrow bandwidth. Good luck and DX. 73 Gary N4AST |
"Neil Gibson" wrote in message ...
I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz. Although it was designed as a mobile I want to use it as a portable, You may think you do, but you really don't..:( Well, maybe if you like radio torture sessions where 100w out works like 5w...:( Only if you were at the beach on salt water, or had 60 or more radials under it for a normal ground mount, would I give it an estimate of doing a half decent job. can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire As noted, a 1/4 wave is appx 60 ft, but one radial is nearly useless at reducing ground losses on a ground mount vertical. And being the vertical is short, and fairly inefficient, the need of a *good* radial or ground system is extra critical. On a car, you just take the ground losses and deal with them, as there is no real choice. But the hustler antenna in itself, is not the best in the west. The coil is fairly lossy. But on the other hand, with one radial, ground losses would likely overshadow coil losses, and it wouldn't matter. :/ What is "portable" going to be? When I run portable, I just string up a quicky dipole, or use my mobile antenna thats on the truck. But my mobile antenna is a good bit better than the hustler...Less coil loss. It's a fairly usable system even on 80m. But I string a dipole in some trees if I want a *real* signal. I also have two of those "drive on" mast holders that you park a wheel on. So I can actually put up masts quite easily portable if no trees are around. I use those cheap 10 ft fence rail sections as mast. Two gives 20 ft, and can be put up easily by one person. Three is too top heavy unless you use extra guying precautions..I've tried lifting three together once, 30 ft" and it was kind hairy...So I just stick with 20 ft worth. It's good enough for the average NVIS stuff I usually work on 80m. MK |
"Neil Gibson" wrote in message ...
I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz. Although it was designed as a mobile I want to use it as a portable, You may think you do, but you really don't..:( Well, maybe if you like radio torture sessions where 100w out works like 5w...:( Only if you were at the beach on salt water, or had 60 or more radials under it for a normal ground mount, would I give it an estimate of doing a half decent job. can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire As noted, a 1/4 wave is appx 60 ft, but one radial is nearly useless at reducing ground losses on a ground mount vertical. And being the vertical is short, and fairly inefficient, the need of a *good* radial or ground system is extra critical. On a car, you just take the ground losses and deal with them, as there is no real choice. But the hustler antenna in itself, is not the best in the west. The coil is fairly lossy. But on the other hand, with one radial, ground losses would likely overshadow coil losses, and it wouldn't matter. :/ What is "portable" going to be? When I run portable, I just string up a quicky dipole, or use my mobile antenna thats on the truck. But my mobile antenna is a good bit better than the hustler...Less coil loss. It's a fairly usable system even on 80m. But I string a dipole in some trees if I want a *real* signal. I also have two of those "drive on" mast holders that you park a wheel on. So I can actually put up masts quite easily portable if no trees are around. I use those cheap 10 ft fence rail sections as mast. Two gives 20 ft, and can be put up easily by one person. Three is too top heavy unless you use extra guying precautions..I've tried lifting three together once, 30 ft" and it was kind hairy...So I just stick with 20 ft worth. It's good enough for the average NVIS stuff I usually work on 80m. MK |
Neil, By now, you have probably figured out that the 'Hustler' antenna as a portable isn't exactly the best idea without a very good ground system. But, it will work with a counterpoise. Not well, but it will work. Something in the near 'neighborhood' of a 1/4 wave for the counterpoise's length should make the transmitter 'see' a load it can work into (depending on how that counterpoise is 'laid out'). There are other options for a portable antenna that may work better than an extremely shortened mobile antenna... 'Doc |
You know, one wonders what happens if you swap the Hustler and the
counterpoise? Coax center to a quarter wave piece of wire, shield to a (ugh! I had one once) Hustler not too near the ground. Nothing different probably, but you never know. -- Crazy George Remove N O and S P A M imbedded in return address "'Doc" wrote in message ... Neil, By now, you have probably figured out that the 'Hustler' antenna as a portable isn't exactly the best idea without a very good ground system. But, it will work with a counterpoise. Not well, but it will work. Something in the near 'neighborhood' of a 1/4 wave for the counterpoise's length should make the transmitter 'see' a load it can work into (depending on how that counterpoise is 'laid out'). There are other options for a portable antenna that may work better than an extremely shortened mobile antenna... 'Doc |
And, one other idea !! (found on the bay of "e"), and available elsewhere- a mount for 2 of these (or the hustler, and an Iron Horse, ect) "1/4" wave antenna -- first antenna goes to center of coax, second goes to shield!! makes a dipole, about 15 foot long, and can be mounted to mast (conductive, or plastic, same diff! tho the impedence will be quite low (because of these loaded whips), and the effeciency will be also not the best, at least would be an effective counterpoise!! and, to boot, parts available to build adaptor at rip-off shack!! got whole thing off epay for about 50 bux, + shipping!! Jim NN7K "Crazy George" wrote in message ... You know, one wonders what happens if you swap the Hustler and the counterpoise? Coax center to a quarter wave piece of wire, shield to a (ugh! I had one once) Hustler not too near the ground. Nothing different probably, but you never know. -- Crazy George Remove N O and S P A M imbedded in return address "'Doc" wrote in message ... Neil, By now, you have probably figured out that the 'Hustler' antenna as a portable isn't exactly the best idea without a very good ground system. But, it will work with a counterpoise. Not well, but it will work. Something in the near 'neighborhood' of a 1/4 wave for the counterpoise's length should make the transmitter 'see' a load it can work into (depending on how that counterpoise is 'laid out'). There are other options for a portable antenna that may work better than an extremely shortened mobile antenna... 'Doc |
BTW that is Both Antennas, and the adaptor- not too expensive- cheaper when
need only one ant, and the adaptor. "Jim" wrote in message ... And, one other idea !! (found on the bay of "e"), and available elsewhere- a mount for 2 of these (or the hustler, and an Iron Horse, ect) "1/4" wave antenna -- first antenna goes to center of coax, second goes to shield!! makes a dipole, about 15 foot long, and can be mounted to mast (conductive, or plastic, same diff! tho the impedence will be quite low (because of these loaded whips), and the effeciency will be also not the best, at least would be an effective counterpoise!! and, to boot, parts available to build adaptor at rip-off shack!! got whole thing off epay for about 50 bux, + shipping!! Jim NN7K "Crazy George" wrote in message ... You know, one wonders what happens if you swap the Hustler and the counterpoise? Coax center to a quarter wave piece of wire, shield to a (ugh! I had one once) Hustler not too near the ground. Nothing different probably, but you never know. -- Crazy George Remove N O and S P A M imbedded in return address "'Doc" wrote in message ... Neil, By now, you have probably figured out that the 'Hustler' antenna as a portable isn't exactly the best idea without a very good ground system. But, it will work with a counterpoise. Not well, but it will work. Something in the near 'neighborhood' of a 1/4 wave for the counterpoise's length should make the transmitter 'see' a load it can work into (depending on how that counterpoise is 'laid out'). There are other options for a portable antenna that may work better than an extremely shortened mobile antenna... 'Doc |
George, It does that every half cycle... 'Doc |
On Thu, 6 May 2004 22:04:39 +0100, "Neil Gibson"
wrote: I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz. Although it was designed as a mobile I want to use it as a portable, can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire Use another RM-80 as the counterpoise. Ron |
Jim wrote:
And, one other idea !! (found on the bay of "e"), and available elsewhere- a mount for 2 of these (or the hustler, and an Iron Horse, ect) "1/4" wave antenna -- first antenna goes to center of coax, second goes to shield!! makes a dipole, about 15 foot long, and can be mounted to mast (conductive, or plastic, same diff! tho the impedence will be quite low (because of these loaded whips), and the effeciency will be also not the best, at least would be an effective counterpoise!! and, to boot, parts available to build adaptor at rip-off shack!! got whole thing off epay for about 50 bux, + shipping!! Jim NN7K What do you consider to be the purpose(s) of a counterpoise? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Jim wrote:
BTW that is Both Antennas, and the adaptor- not too expensive- cheaper when need only one ant, and the adaptor. It works well enough above 14 MHz, but such an antenna for 75m is a real dog. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Ron wrote:
I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz. Although it was designed as a mobile I want to use it as a portable, can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire Use another RM-80 as the counterpoise. Hmmmmm, a 2% efficient antenna with a 2% efficient counterpoise. :-) -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Hey Cecil, 4% is better than 2%, and a 'hunerd'% increase
in efficiency! (I agree with you anyway...) 'Doc |
'Doc wrote:
Hey Cecil, 4% is better than 2%, and a 'hunerd'% increase in efficiency! (I agree with you anyway...) A 2% efficient radiator and a 2% efficient counterpoise doesn't add up to 4% total efficiency. :-) Anyone who wants a portable rotatable dipole on 75m can do much, much better than two Hustlers. Two SD-20 poles with high-Q loading coils in the middle of each comes to mind. And that's not much more trouble than two Hustlers. The SD-20 approach is available at http://www.wr6w6.com -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Counterpoise is required for most antennas to operate "effeciently" (have
you ever tried to load a 1/4 wave whip (without one)? Makes great dummy load! Dont radiate worth a darn! Needs the full "1/2 wave" to radiate effectively say that as can be done with loading coils, ect to shorten the effective length, or a ground media for the 1/4 part to work against (tho, at vhf there are SOME 1/2 wave , base coupled antennas that need no counter poise-- but then talking 75 meters- 125 foot tower to do that!! Cecil wrote: Jim wrote: And, one other idea !! (found on the bay of "e"), and available elsewhere- a mount for 2 of these (or the hustler, and an Iron Horse, ect) "1/4" wave antenna -- first antenna goes to center of coax, second goes to shield!! makes a dipole, about 15 foot long, and can be mounted to mast (conductive, or plastic, same diff! tho the impedence will be quite low (because of these loaded whips), and the effeciency will be also not the best, at least would be an effective counterpoise!! and, to boot, parts available to build adaptor at rip-off shack!! got whole thing off epay for about 50 bux, + shipping!! Jim NN7K What do you consider to be the purpose(s) of a counterpoise? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Oh, and BTW, never stated it would be the "Best" antenna, But, surely would
be easier to pack, and set up, then packing a roll of wire , aprox. 67 feet long, and haveing to retrieve it later!! and, would be willing to bet, even as lousey is this is, would beat that one manufactured by a certain outfit that is about 3 foot high, and LOADS up your coax (ISO-T) to avoid lawsuits, like they involved 73 in years ago . Ron-er Jim NN7K Counterpoise is required for most antennas to operate "effeciently" (have you ever tried to load a 1/4 wave whip (without one)? Makes great dummy load! Dont radiate worth a darn! Needs the full "1/2 wave" to radiate effectively say that as can be done with loading coils, ect to shorten the effective length, or a ground media for the 1/4 part to work against (tho, at vhf there are SOME 1/2 wave , base coupled antennas that need no counter poise-- but then talking 75 meters- 125 foot tower to do that!! Cecil wrote: Jim wrote: And, one other idea !! (found on the bay of "e"), and available elsewhere- a mount for 2 of these (or the hustler, and an Iron Horse, ect) "1/4" wave antenna -- first antenna goes to center of coax, second goes to shield!! makes a dipole, about 15 foot long, and can be mounted to mast (conductive, or plastic, same diff! tho the impedence will be quite low (because of these loaded whips), and the effeciency will be also not the best, at least would be an effective counterpoise!! and, to boot, parts available to build adaptor at rip-off shack!! got whole thing off epay for about 50 bux, + shipping!! Jim NN7K What do you consider to be the purpose(s) of a counterpoise? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Sat, 08 May 2004 09:12:50 -0500, Cecil Moore
wrote: Ron wrote: I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz. Although it was designed as a mobile I want to use it as a portable, can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire Use another RM-80 as the counterpoise. Hmmmmm, a 2% efficient antenna with a 2% efficient counterpoise. :-) Hmmmm, I wonder what 2% efficient means. 2% radiated power with 98% reflected back into the radio? Ability to contact only 2% of the stations that you can receive? What? Ron, W1WBV |
On Sat, 08 May 2004 13:51:15 -0500, Cecil Moore
wrote: 'Doc wrote: Hey Cecil, 4% is better than 2%, and a 'hunerd'% increase in efficiency! (I agree with you anyway...) A 2% efficient radiator and a 2% efficient counterpoise doesn't add up to 4% total efficiency. :-) Anyone who wants a portable rotatable dipole on 75m can do much, much better than two Hustlers. Two SD-20 poles with high-Q loading coils in the middle of each comes to mind. And that's not much more trouble than two Hustlers. The SD-20 approach is available at http://www.wr6w6.com The question was the length of a counterpoise, not a rotatable dipole. I figured another Hustler sure beats running radials out in a portable situation. If someone was to ask you how to make their Chevy run better would you tell him to get a Ford? ;-) Ron |
Ron wrote:
wrote: Hmmmmm, a 2% efficient antenna with a 2% efficient counterpoise. :-) Hmmmm, I wonder what 2% efficient means. 2% radiated power with 98% reflected back into the radio? Ability to contact only 2% of the stations that you can receive? What? It's a ballpark estimate and means for every 100 watts going into the antenna, two watts are radiated. If the feedpoint impedance is 50 ohms, 98 watts are dissipated as heat in the antenna, primarily in the coil(s). (Try transmitting 100w into a 75m hamstick for one minute and then grabbing the coil.) -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Ron wrote:
I figured another Hustler sure beats running radials out in a portable situation. Maybe so, and I figured a slightly different approach would triple the radiated power. Anyone who uses a mobile antenna for portable operation on 75m is simply wasting power since portable antennas invariably can be longer/higher. If someone was to ask you how to make their Chevy run better would you tell him to get a Ford? ;-) No, but if someone asks me how to make their Ford run better, I would tell him to get a Chevy. :-) -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Taking Cecil's example a step further. The radiation resistance [Rr] of
an 8 foot antenna at 3.9 MHz is in the range of 1 to 2 ohms depending upon coil location. The antenna losses, I^2*R, can be in the range of 10 to 20 ohms [Ra], and the ground losses can be in the range of 10 to 20 ohms {Rg]. So, your nominal '50 ohm load' is comprised of Rr + Ra + Rg = RL. Efficiency is (Rr/RL)*100%. So, 2/50 = 4% or 1/50 = 2%. Take your pick! The energy is NOT reflected back. It is wasted as heat in the antenna and ground losses! Deacon Dave, W1MCE + + + Ron wrote: On Sat, 08 May 2004 09:12:50 -0500, Cecil Moore wrote: Ron wrote: I have a Hustler amateur mobile antenna model RM-80 for 80 Meter 25-30 KHz. Although it was designed as a mobile I want to use it as a portable, can anybody tell me the length of the counterpoise needed for this model? or can I just use an earth wire Use another RM-80 as the counterpoise. Hmmmmm, a 2% efficient antenna with a 2% efficient counterpoise. :-) Hmmmm, I wonder what 2% efficient means. 2% radiated power with 98% reflected back into the radio? Ability to contact only 2% of the stations that you can receive? What? Ron, W1WBV |
On Sun, 09 May 2004 11:35:42 -0500, Cecil Moore
wrote: Ron wrote: I figured another Hustler sure beats running radials out in a portable situation. Maybe so, and I figured a slightly different approach would triple the radiated power. Anyone who uses a mobile antenna for portable operation on 75m is simply wasting power since portable antennas invariably can be longer/higher. If someone was to ask you how to make their Chevy run better would you tell him to get a Ford? ;-) No, but if someone asks me how to make their Ford run better, I would tell him to get a Chevy. :-) Well, now, that's more like it :-) Ron |
On Sun, 09 May 2004 17:26:05 GMT, Dave Shrader
wrote: Taking Cecil's example a step further. The radiation resistance [Rr] of an 8 foot antenna at 3.9 MHz is in the range of 1 to 2 ohms depending upon coil location. The antenna losses, I^2*R, can be in the range of 10 to 20 ohms [Ra], and the ground losses can be in the range of 10 to 20 ohms {Rg]. So, your nominal '50 ohm load' is comprised of Rr + Ra + Rg = RL. So you can use the formula I^2*R (which is for finding P) without knowing the variable "I" to find the resistance (Ra)? I don't think so. Unless you have a magic wand, Harry Potter :-) Ron Efficiency is (Rr/RL)*100%. So, 2/50 = 4% or 1/50 = 2%. Take your pick! The energy is NOT reflected back. It is wasted as heat in the antenna and ground losses! Deacon Dave, W1MCE + + + |
Ron wrote:
On Sun, 09 May 2004 17:26:05 GMT, Dave Shrader wrote: SNIP So you can use the formula I^2*R (which is for finding P) without knowing the variable "I" to find the resistance (Ra)? I don't think so. Unless you have a magic wand, Harry Potter :-) Ron You certainly can!! Total power to the antenna SYSTEM = I^2*(Rr + Ra + Rg). Total power radiated = I^2*(Rr). When you divide the two terms to get efficiency the I^2 term cancels. This leaves Rr/(Rr + Ra + Rg). The current terms drops right out!! DD |
Dave,
I didn't come here to fence with you guys. I know nothing about the relative efficiency of antenna systems. You could be right and the effiency of a tuned dipole "may" be 2%, which in my mind means if it were replaced with a regular dipole, the signal strength at a remote location would increase 50 times, but that certainly cannot be determined that with that brand of math. Sorry, Ron On Mon, 10 May 2004 00:20:55 GMT, Dave Shrader wrote: Ron wrote: On Sun, 09 May 2004 17:26:05 GMT, Dave Shrader wrote: SNIP So you can use the formula I^2*R (which is for finding P) without knowing the variable "I" to find the resistance (Ra)? I don't think so. Unless you have a magic wand, Harry Potter :-) Ron You certainly can!! Total power to the antenna SYSTEM = I^2*(Rr + Ra + Rg). Total power radiated = I^2*(Rr). When you divide the two terms to get efficiency the I^2 term cancels. This leaves Rr/(Rr + Ra + Rg). The current terms drops right out!! DD |
Yes it can! Gain improvement = 10*Log{50) = +16 dB or about 3 S-units.
Ron wrote: Dave, I didn't come here to fence with you guys. I know nothing about the relative efficiency of antenna systems. You could be right and the effiency of a tuned dipole "may" be 2%, which in my mind means if it were replaced with a regular dipole, the signal strength at a remote location would increase 50 times, but that certainly cannot be determined that with that brand of math. Sorry, Ron On Mon, 10 May 2004 00:20:55 GMT, Dave Shrader wrote: Ron wrote: On Sun, 09 May 2004 17:26:05 GMT, Dave Shrader wrote: SNIP So you can use the formula I^2*R (which is for finding P) without knowing the variable "I" to find the resistance (Ra)? I don't think so. Unless you have a magic wand, Harry Potter :-) Ron You certainly can!! Total power to the antenna SYSTEM = I^2*(Rr + Ra + Rg). Total power radiated = I^2*(Rr). When you divide the two terms to get efficiency the I^2 term cancels. This leaves Rr/(Rr + Ra + Rg). The current terms drops right out!! DD |
On Mon, 10 May 2004 11:41:10 GMT, Dave Shrader
wrote: Yes it can! Gain improvement = 10*Log{50) = +16 dB or about 3 S-units. I already gave up. You know more about the subject than me. Just a question, is W1MCE your original call? Ron W1WBV (1952) |
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