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Grove's Flex-tenna
I just built Bob Grove's "Flex Antenna." It works great!! The HF version
is perfect for those of us who travel. Just FYI. HB |
Grove's Flex-tenna
In article ypQag.3267$RY2.1797@trnddc02, "Hunchy"
wrote: I just built Bob Grove's "Flex Antenna." It works great!! The HF version is perfect for those of us who travel. Just FYI. That's nice. What are the design details? If I was to guess it looks like a common mode antenna where only the center conductor is electrically connected to the radio. At the coax far end from the radio the center and shield are connected together. This would not be a good antenna in an electrically noisy environment. -- Telamon Ventura, California |
Grove's Flex-tenna
In article ,
"Lisa Simpson" wrote: "Hunchy" wrote in message news:ypQag.3267$RY2.1797@trnddc02... I just built Bob Grove's "Flex Antenna." It works great!! The HF version is perfect for those of us who travel. Just FYI. What edition of MT was that one in? I'll give it a whirl . . . Grove is selling it for $9.95 -- Telamon Ventura, California |
Grove's Flex-tenna
Telamon,
From the description it appears to be simply 24 Feet of a Single (1) Wire {Heavy Gauge} Speaker Wire connected to an "F" Connector as the FLEX-TENNA -by- Grove Enterprises http://www.grove-ent.com/grovehvu.html I think that one of those Roll-Up {Reel} Portable Shortwave Antenna's would do about the same as the Grove Flex-Tenna for Shortwave Listening. http://www.shortwavestore.com/sws/pr...?productid=612 http://www.durhamradio.com/s/product...roductid=44948 http://www.amazon.com/gp/product/B00...lance&n=172282 http://images.amazon.com/images/P/B0...CLZZZZZZZ_.gif http://www.survivalunlimited.com/radios/antenna.htm http://www.universal-radio.com/catal...able/3184b.jpg http://www.ccrane.com/antennas/short...e-antenna.aspx iane ~ RHF |
Grove's Flex-tenna
In article .com,
"RHF" wrote: Telamon, From the description it appears to be simply 24 Feet of a Single (1) Wire {Heavy Gauge} Speaker Wire connected to an "F" Connector as the FLEX-TENNA -by- Grove Enterprises http://www.grove-ent.com/grovehvu.html I think that one of those Roll-Up {Reel} Portable Shortwave Antenna's would do about the same as the Grove Flex-Tenna for Shortwave Listening. http://www.shortwavestore.com/sws/pr...?productid=612 http://www.durhamradio.com/s/product...roductid=44948 http://www.amazon.com/gp/product/B00...v=glance&n=172 282 http://images.amazon.com/images/P/B0...CLZZZZZZZ_.gif http://www.survivalunlimited.com/radios/antenna.htm http://www.universal-radio.com/catal...able/3184b.jpg http://www.ccrane.com/antennas/short...e-antenna.aspx You could be right about it being just a single insulated wire but use of the word cable usually means transferring a signal from one place to another. Complete electrical paths require two wires at a minimum because as any engineer knows for a circuit to be a complete path a loop forms with one wire carrying current to the load and the other wire carrying it back to the source according to basic circuit analysis. The description states "No ground or radials are required." indicating that the antenna is somehow balanced and not single element common mode. Also a plural is used in this descriptive sentence "Its vinyl-protected wire elements allow the Flex-Tenna" indicating more than one conductor is used but maybe I read to much into the description. -- Telamon Ventura, California |
Grove's Flex-tenna
Get a large empty wood sewing thread spool.Wind 24 feet of Bell wire
around it.Very cheap and very easy. cuhulin |
Grove's Flex-tenna
Telamon,
I have to order one of the Flex-Tennas by Grove Ent. and see-for-my-own-self - What It Be ? ~ RHF GROVE FLEX-TENNA™ HVU -by- Grove Enterprises Price as Listed $14.95 Grove Part # ANT45 FLEX-TENNA = http://www.grove-ent.com/grovehvu.html The 24-foot Model HVU Flex-Tenna™ is a thin and inconspicuous, Flexible-Wire Antenna designed to provide continuous 10 kHz to 2500 MHz reception on Shortwave Receivers, wide-frequency- coverage receivers and scanners with only one antenna connector. Since it's a narrow length of clear-insulated cable, it is an excellent . . .. . |
Grove's Flex-tenna
HUnchy,
Can you describe what you built in detail to us; so that we have a better idea of exactly What the Flex Antenna "IS" ? i want to know ~ RHF |
Grove's Flex-tenna
On 19 May 2006 02:26:59 -0700, "RHF"
wrote: HUnchy, Can you describe what you built in detail to us; so that we have a better idea of exactly What the Flex Antenna "IS" ? i want to know ~ RHF . . . . Mayhaps much ado about nada... the Grove dealie bears a remarkable resemblance to the external antenna that Sony packed with my 2010. Sony has 23.5 feet of stranded wire with a clip at one end, a plug at the other end. Nothing else... bob k5qwg |
Grove's Flex-tenna
In article .com,
"RHF" wrote: Telamon, I have to order one of the Flex-Tennas by Grove Ent. and see-for-my-own-self - What It Be ? ~ RHF GROVE FLEX-TENNA™ HVU -by- Grove Enterprises Price as Listed $14.95 Grove Part # ANT45 FLEX-TENNA = http://www.grove-ent.com/grovehvu.html The 24-foot Model HVU Flex-Tenna™ is a thin and inconspicuous, Flexible-Wire Antenna designed to provide continuous 10 kHz to 2500 MHz reception on Shortwave Receivers, wide-frequency- coverage receivers and scanners with only one antenna connector. Since it's a narrow length of clear-insulated cable, it is an excellent Why don't you just send Grove an email or phone them and ask the question? -- Telamon Ventura, California |
Grove's Flex-tenna
It will probally be as dead on arrival as that Tiny-Tenna I wasted about
ten dollars,plus shipping and handling charges on from Mr.Tiny-Tenna about ten or twelve years ago. cuhulin |
Grove's Flex-tenna
Grove ought to send me one to try out for free and I will give out me
expert opinion.Grove pays it all,both ways.Grove,I am getting NOT to trust y'all anymore. cuhulin |
Grove's Flex-tenna
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Grove's Flex-tenna
Telamon,
I am a Hands-on-Kind-of-Guy and Seeing-Is-Believing we'll see ~ RHF |
Grove's Flex-tenna
Any old thing works fine on modern portable SW's, as far as pulling
in signal. You can't get extravagant or most receivers will overload with the strong signals around and give you horrible images all over the band. So the modest wind-up antennas are about the best you can do. You get differences in rejection of local noise, and for doing that you need grounding and matching transformers and distant antennas, or some ability to steer a null on noise sources at least, to get away from the local sources somewhat. So I expect the feature here is invisible wire, the better to meet the local homeowner association objections or the wife's moods, and beyond that it's a reel antenna that comes with some portables, but they have black wire you can see and this doesn't. -- Ron Hardin On the internet, nobody knows you're a jerk. |
Grove's Flex-tenna
For One and All,
The Grove {Hidden] Flex-Tenna has arrived along with the Grove SW Pocket-Tenna for Wideband Handheld Receivers. http://www.grove-ent.com/shortwaveantennas.html report to follow - iane ~ RHF |
The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna
Telamon - Your discription requires some thinking ~ RHF
19 Feet Coax & 5 Feet Wire ===================| o------------------------------------|----- ===================| Some how i think it comes out 19 Feet & 5 Feet -------------------|----- o 'o' = Feed Point |
The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna
In article .com,
"RHF" wrote: Telamon wrote: In article .com, "RHF" wrote: Telamon wrote: In article . com, "RHF" wrote: JHR, The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna http://groups.yahoo.com/group/Shortw...a/message/9886 Yes having the two Wires Parallel and within an 1/8" of each other should effectively have the signals cancel each other out. - B U T - The Wires are not the same length and therefore a-differential is created between the two signal levels in the two Wires. Because In-Fact the Two Wires are of Different Wave Lengths. One must 'assume' that Grove did some Design Planning or practical Trial-and-Error Testing to get the Length of the Two Wires so that they would give good results across the HF, VHF and UHF Bands. * 24 Feet is a little short for a 1/4 WL for the 31 Metre Band. * 19 Feet is a little short for a 1/4 WL for the 25 Metre Band. For Shortwave {High Frequency Only} one might try building the same type of "Flex-Tenna Antenna made from Speaker Wire with Two Wires that are a little Longer and have a Greater 'difference' in the Wave Lengths : Shortwave Upper-Middle Bands : * 38 Feet (a little short) for a 1/4 WL for the 49 Metre Band. * 24 Feet (a little short) for a 1/4 WL for the 31 Metre Band. = Delta of 14 Feet Shortwave Lower - Middle Bands : * 47 Feet (a little short) for a 1/4 WL for the 60 Metre Band. * 31 Feet (a little short) for a 1/4 WL for the 41 Metre Band. = Delta of 16 Feet NOTE - The Flex-Tenna Antenna design lends itself to Speaker Wire; Twin-Lead and Ladder-Line "Parallel" Wire type wire-structures. Coax Cable for this Design of Antenna would not work IMHO. The Outer-Shield of the Coax Cable would effectively Shield the Section of the Inner Conductor of the Coax Cable and thus only result in the Shield and Delta-Tip functioning as the 'differential' Wire Antenna Elements. FWIW - Most of the Coax Cable 'Liner' Antenna Designs are basically End-Fed Dipoles beginning with a 1/4 WL of Coax Shield with an ending with 1/4 WL of Exposed Inner Conductor. The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna http://groups.yahoo.com/group/Shortw...a/message/9818 You could make a similar antenna out of coax but it would be more bulky than the Grove version. You can make loop antennas with coax that are balanced antennas. The loops made of coax can be made sensitive to the E and M fields or just the M field. You could use the speaker wire to make a loop antenna that was sensitive to the E and M fields. Telamon, Maybe someone could do some modeling of these two types of Wire Antenna First a piece of Speaker Wire with one Wire 24 Feet long and the other Wire 19 Feet long using an "F" Connector at the common Feed-Point-End. Second a piece of Coax Cable with the Outer Shield Terminated at 19 Feet and the Inner Conductor with the Insulation still around it continuing for another Five Feet for a Total Length of 24 Feet - again using an "F" Connector at the common Feed-Point-End. Some How I Do Not Think That They Are The Same Antenna. but i could be wrong -and- you could be right - iane ~ RHF Yeah, that would not. I was think more along the lines of: Starting from the radio the coax center conductor goes to the antenna jack tip and the shield is not connected to anything. This coax is 19 feet long. At the coax far end the center conductor and shield are connected together and a single insulated wire continues another five feet starting at the center/shield junction. Telamon - Your discription requires some thinking ~ RHF 19 Feet Coax & 5 Feet Wire ===================| o------------------------------------|----- ===================| Some how i think it comes out 19 Feet & 5 Feet -------------------|----- o The shield is a 19 foot element and the 5 foot single insulated wire is a continuation of it where the connection to this element is offset from the end by 5 feet. -- Telamon Ventura, California |
Grove Shortwave (SW) Pocket-Tenna
GW,
The Grove Shortwave (SW) Pocket-Tenna Antenna was http://www.grove-ent.com/pocket-tenna.html mainly designed by Grove for Hand Held Scanners or "All Band" {HF-VHF-UHF} Hand Held Radios which simply had a small short Flexible Whip {Rubber Ducky} Antenna often connected to them using a BNC Connector. http://groups.yahoo.com/group/Shortw...a/message/9935 First the BNC Connector - Designed for Hand Held Scanners and Radios that often use them as an Antenna Connector and Input. Second the Length {Size} - Most of these Hand Held Scanners and Radios will OverLoad when a Larger Long Wire Antenna : Say a Dipole 'cut' for the 31 Meter Band is used with them rendering them useless. - - - 31 Meter Dipole Antenna 49 Feet Tip-to-Tip. I would suspect that Grove did a few Trial-and-Error 'design' {Prototype} Antennas and found that about Twenty Feet was all that most of these Hand Held Scanners and Radios could handle before 'Size' {Length} caused a problem with "OverLoading" the Radio's RF Front-End. Note - This is about the same length as the 23 Foot Portable Reel {Roll-Up} Shortwave Antennas that come with, or can be purchased for most 'portable' AM / FM Shortwave Radios. Again many of these 'portable' AM / FM Shortwave Radios will "OverLoad" when a Larger Long Size Antenna is used with them. Third - What to call {Label} this Antenna : # 1 - It is End-Fed. {End-Fed} # 2 - It is made from a single piece of Coax Cable {Liner} and designed to have Two Equal Sections made-up of the Coax Shield and Exposed Inner Conductor. {Balanced Mono-Pole} # 3 - Not Really designed to be Resonant at any Shortwave (HF) Band and used Across the Shortwave Bands. {All-Band} What's-In-A-Name : End-Fed Liner Mono-Pole All-Band Antenna ? TESTING - Again in a Side-by-Side trail it was my observation using the 20 Foot Grove Shortwave (SW) Pocket-Tenna -vice- 23 Foot Portable Reel {Roll-Up} Shortwave Antenna with a Grundig Satellit 800 Millennium Radio that the Grove had as good a signal with less noise then the Roll-Up. * Roll-Up connected via the Red HI-Z Terminal No-Ground. * Grove connected via the SO-239 LO-Z Jack No-Ground. THE QUESTIONS : ? Is the Grove a Great Shortwave Antenna ? -NO- ? For It's Intended Use - Does the Grove Antenna Work ? -YES- ? Is the Grove Worth $20 ? -YES and NO- -Yes- Price about Right for those who simply want to Buy It to Use. -No- Easy to Do-It-Yourself : If you have the Skills and Knowledge plus the Tools and Materials to build it. AGAIN THE [MY] BOTTOM LINE : The Grove Shortwave (SW) Pocket-Tenna http://www.grove-ent.com/pocket-tenna.html Simple enough to build-it-yourself to play around with and low cost enough to simply buy-it-and-try-it. - - - In , http://groups.yahoo.com/group/Shortw...a/message/9931 - - - "Greg W:-)" onegammyleg@... wrote: iane ~ RHF |
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