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type/length of wire and connectors for external antenna?
On Oct 4, 4:15*am, Wimpie wrote:
On 2 oct, wrote: I'd like to try an external antenna, but one was not included with my G5. What type ofwireshould I get (stranded, solid, gauge, insulated...), and do I just solder it to the pos or neg lead of a miniplug to go into the ext antenna receptacle? Thanks.... Jim Hello Jim, Every type of metalwirewill work for you situation (solid, stranded, plasticized galvanized washing line, etc). Most modern SW receivers with internal antennas are very sensitive, but cannot handle strong signals, so longer will not always be better. To reduce the interference from electronic equipment close to your SW receiver, you may put a coaxial cable between the actual antenna and the receiver. You can use any type of 75, 90 or 50 Ohms cable. The center conductor goes to the center pin of the mini plug and the bread goes to the ground of the mini plug. The antenna side of the cable needs some clarification. The antennawiregoes to the center conductor of the cable, the braid should be connected to ground outside your house (or at least far away from where you expect or have interference). What is "ground"? *When you live in an apartment, it can be the metal fence or railing of the balcony. *You can use a ground rod or any other large metallic structure outside your house. Connect the braid of the cable directly to the ground structure. Do not insert a long run ofwirebetween the metal structure and the braid of the coaxial cable. For some form of static / impulse protection you may add a 1… 3 uH inductor between the center conductor and the braid. Note that this inductor will attenuate AM broadcast band reception. As others said, you have to experiment with the orientation of thewireto get best signal/noise ratio. When you are very limited in space for thewire, you may use some 5..10 feet of chicken mesh as reception antenna or use more wires in a fan shape. Best regards, Wim PA3DJSwww.tetech.nl please remove abc when using PM. OK, sorry, I see I was confusing the antenna and radio sides of the coax. The radio side: center of coax to center of mini, shield brain to surround of mini. Antenna side: braid to ground post, center to antenna wire. So I can have the run between outside ground post and radio using coax. But can I damage G5 with an external wire? If so I'll use the whip inductor. Please advise.... thanks Jim |
#2
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type/length of wire and connectors for external antenna?
Hello Jim,
On 11 oct, 18:10, JimK wrote: On Oct 4, 4:15*am, Wimpie wrote: On 2 oct, wrote: I'd like to try an external antenna, but one was not included with my G5. What type ofwireshould I get (stranded, solid, gauge, insulated...), and do I just solder it to the pos or neg lead of a miniplug to go into the ext antenna receptacle? Thanks.... Jim Hello Jim, Every type of metalwirewill work for you situation (solid, stranded, plasticized galvanized washing line, etc). Most modern SW receivers with internal antennas are very sensitive, but cannot handle strong signals, so longer will not always be better. To reduce the interference from electronic equipment close to your SW receiver, you may put a coaxial cable between the actual antenna and the receiver. You can use any type of 75, 90 or 50 Ohms cable. The center conductor goes to the center pin of the mini plug and the bread goes to the ground of the mini plug. The antenna side of the cable needs some clarification. The antennawiregoes to the center conductor of the cable, the braid should be connected to ground outside your house (or at least far away from where you expect or have interference). What is "ground"? *When you live in an apartment, it can be the metal fence or railing of the balcony. *You can use a ground rod or any other large metallic structure outside your house. Connect the braid of the cable directly to the ground structure. Do not insert a long run ofwirebetween the metal structure and the braid of the coaxial cable. For some form of static / impulse protection you may add a 1… 3 uH inductor between the center conductor and the braid. Note that this inductor will attenuate AM broadcast band reception. As others said, you have to experiment with the orientation of thewireto get best signal/noise ratio. When you are very limited in space for thewire, you may use some 5..10 feet of chicken mesh as reception antenna or use more wires in a fan shape. Best regards, Wim PA3DJSwww.tetech.nl please remove abc when using PM. OK, sorry, I see I was confusing the antenna and radio sides of the coax. The radio side: center of coax to center of mini, shield brain to surround of mini. * OK Antenna side: braid to ground post, center to antenna wire. So I can have the run between outside ground post and radio using coax. OK, working this way avoids that the cable picks up interference from domestic equipment. But can I damage G5 with an external wire? If so I'll use the whip inductor. Please advise.... Yes, you can, as most of these portable recievers do not have strong input protection, nearby strikes can damage the input. Don't make the wire longer then necessary and remove the mini plug from the radio in case of natural photo flash. You might add the inductor or resistor to lower the risk on damage because of built-up of static electricity. Using a special transformer as mentioned in other postings gives you more signal output in case of short wires. So you can have a shorter wire (for example when you have limited space). I do not share the opinion that these transformers reduce interference significantly. When you live in a residential area, you probably don't need this as noise will be dominant with moderate wire lengths. More signal does not always mean better reception as noise will raise also. thanks Jim Best regards, Wim PA3DJS www.tetech.nl |
#3
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type/length of wire and connectors for external antenna?
Thanks again, everyone.
But can I damage G5 with an external wire? If so I'll use the whip inductor. Please advise.... Yes, you can, as most of these portable recievers do not have strong input protection, *nearby strikes can damage the input. *Don't make the wire longer then necessary and remove the mini plug from the radio in case of natural photo flash. You might add the inductor or resistor to lower the risk on damage because of built-up of static electricity. Wim (or anyone), So, an early post stated "the longer the better" but you say not so long. What is a good length to try? I assume I'll want to experiment with longer and shorter. Bought 24 gauge speaker wire, 100 ft. for $6.50 at Home Depot. But I'm nervous now, I don't want to do anything until I understand. I presume you mean, disconnect the antenna during storms with lightening flashes. OK. So, I'm thinking there are three kinds of potential damage from a long wi static, lightening, and overload from a strong signal. There are four ways to connect the antenna that I've encountered: miniplug into antenna out, alligator clip to whip, bare wire wrapped around whip, and inductive coupler (insulated wire wrapped around tube placed over whip). (Leaving the balun out for the moment) Am I right that too strong a radio signal (from too long a wire) can hurt the radio? I presume this is true anytime too strong a signal reaches the inside electronics. But my brother tells me the whip is connected to an internal amplifier that the antenna input jack is not connected to. So maybe the antenna input jack is safe in terms of overloading signal from the long wire. And maybe the inductor can also induce too strong a signal in the antenna which is then amplified, causing damage, is this so? So, connecting the wire via the antenna out jack and miniplug is safe with regard to overload, but inductive coupler, alligator clip on whip, and bare wire wrapping around whip (i.e., all connections to whip) are not. True? As for lightening, it seems all connection methods are dangerous. For static, all but the inductive coupler are dangerous. Right? Using a special transformer as mentioned in other postings gives you more signal output in case of short wires. So you can have a shorter wire (for example when you have limited space). I do not share the opinion that these transformers *reduce interference significantly. When you live in a residential area, you probably don't need this as noise will be dominant with moderate wire lengths. * More signal does not always mean better reception as noise will raise also. If I can figure out how to safely connect the antenna to the radio, then is a good way to solve this noise issue to use a very long wire? Or will it just pick up more residential EMG noise? I am in a residential area, I have apartment buildings on two sides, 100+ feet away, house on third side. Maybe tuning to wavelengths is the only way to get a wire to elevate signal above noise. Thanks very much! Jim |
#4
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type/length of wire and connectors for external antenna?
Hello Jim, I put my comment between your text
On 18 oct, 07:26, JimK wrote: Thanks again, everyone. But can I damage G5 with an external wire? If so I'll use the whip inductor. Please advise.... Yes, you can, as most of these portable recievers do not have strong input protection, nearby strikes can damage the input. Don't make the wire longer then necessary and remove the mini plug from the radio in case of natural photo flash. You might add the inductor or resistor to lower the risk on damage because of built-up of static electricity. Wim (or anyone), So, an early post stated "the longer the better" but you say not so long. What is a good length to try? I assume I'll want to experiment with longer and shorter. Bought 24 gauge speaker wire, 100 ft. for $6.50 at Home Depot. But I'm nervous now, I don't want to do anything until I understand. As you are in a residential area, start with about 20 ft. there may be some bends in the wire (for example some part horizontally, some vertically. I checked the I-manual. The receiver has a DX/LOC switch. When you are listening to a weak station and the clearness doesn’t reduce when switching from DX to LOC, your wire is long enough (maybe somewhat to long for that particular frequency band). I presume you mean, disconnect the antenna during storms with lightening flashes. OK. Correct. So, I'm thinking there are three kinds of potential damage from a long wi static, lightening, and overload from a strong signal. OK, If there is no DC bath between the inner conductor and the shield of the cable, you can have build-up of static charge that may damage the input circuitry. Strong overload (due to strong stations) will very likely not damage the input, but may result in bad reception of signals at certain frequency bands. There are four ways to connect the antenna that I've encountered: miniplug into antenna out, alligator clip to whip, bare wire wrapped around whip, and inductive coupler (insulated wire wrapped around tube placed over whip). (Leaving the balun out for the moment). In my opinion, the insulated wire wrapped around a tube place over the whip, looks like inductive coupling, but is capacitive coupling (no direct electrical connection between wire and whip). This method of coupling reduces the coupling for low frequency. By varying the number of turns you can figure out the best coupling to your receiver. That means sufficient signal from the antenna to overcome the receiver noise, but not too much to get intermodulation (overload) problems. Am I right that too strong a radio signal (from too long a wire) can hurt the radio? I think not, see text above. I presume this is true anytime too strong a signal reaches the inside electronics. But my brother tells me the whip is connected to an internal amplifier that the antenna input jack is not connected to. So maybe the antenna input jack is safe in terms of overloading signal from the long wire. Depends on type of receiver, I don't know the inside of the G5. And maybe the inductor can also induce too strong a signal in the antenna which is then amplified, causing damage, is this so? So, connecting the wire via the antenna out jack and miniplug is safe with regard to overload, but inductive coupler, alligator clip on whip, and bare wire wrapping around whip (i.e., all connections to whip) are not. True? Many portable receivers show overload problems when connecting long wire (for example 100ft) directly to the whip (electrically connected). By wrapping the insulated wire around the whip, you reduce the coupling (especially for the low frequency ranges like AM and LW), hence reducing change of overload. As for lightening, it seems all connection methods are dangerous. For static, all but the inductive coupler are dangerous. Right? Depends. When the wire is insulated from the antenna (what you call inductive coupling), static charge may build-up until it reaches the ultimate strength of the insulation. When exceeded, your whip might be subjected to static discharge. You can bleed the static charge by providing a DC path to ground. Mostly when the bare antenna wire touches the building construction (wood, concrete, etc), static charge will not build-up. Using a special transformer as mentioned in other postings gives you more signal output in case of short wires. So you can have a shorter wire (for example when you have limited space). I do not share the opinion that these transformers reduce interference significantly. When you live in a residential area, you probably don't need this as noise will be dominant with moderate wire lengths. More signal does not always mean better reception as noise will raise also. If I can figure out how to safely connect the antenna to the radio, then is a good way to solve this noise issue to use a very long wire? Or will it just pick up more residential EMG noise? I am in a residential area, I have apartment buildings on two sides, 100+ feet away, house on third side. You may try this. When you have a significant part of the wire outside, away from electronics, that will improve reception, but be aware of overload as mentioned earlier (so use the capacitive coupling with the insulated wire wrapped around the whip). Note that this is not my favorite solution (I prefer the coaxial feed and have all antenna parts away from electronics). Maybe tuning to wavelengths is the only way to get a wire to elevate signal above noise. Sorry Jim, I don't understand what you mean. Thanks very much! Jim I hope my response is not too confusing. Best regards, Wim PA3DJS www.tetech.nl without abc, you have a valid address. |
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