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#1
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Here is a problem that I'm having with my Diamond X700.
Hopefully someone can give me some advice on which antenna would suit my needs best. Problem: My Diamond X700 cost me $400. I'm using it for a VHF repeater antenna. The problem it causes is every now and then, I get gurgling noises and crackling in the transmit and it takes out weak signals. This problem may stay in a few days and be gone for a few days and then come back again. It is not my TX RX duplexer. That was already checked out. I replaced my coax with LMR400. (75 ft. run) I have even changed repeaters and get the same results. Someone told me that the Diamond antennaes are NOT good in repeater service because they whip around and the rods inside do get broken and cause problems and will not show a bad SWR. My SWR is fine. Anyone out here have the same problems that I'm having? Do you have any suggestions on a proper antenna to use? I do have one suggestion and that was to get a Decibel products DB 224 antenna. Their website shows it as 6 DB gain where my Diamond is 9 DB. I'm afraid that I will lose my receive coverage with the lesser DB gain. Can anyone comment on the Decibel product? Any help and suggestions would be appreciated. Or if you can suggest any other antenna that could be used for repeater use at my home. |
#2
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![]() wrote in message ... The problem it causes is every now and then, I get gurgling noises and crackling in the transmit and it takes out weak signals. Does this happen after a rainstorm? There is an internal coil at the base of your antenna (including a tapping capacitor). If water is entering the casing of the antenna, you will have problems (regardless of being used as a repeater antenna or not). |
#3
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First of all, I recommend the DB 224 as a repeater antenna any day over a
Diamond antenna. The DB 224 is a true 6db over a dipole and is the workhorse antenna in the 2-way commercial industry. The Diamond just says 9db.....over what????? What does the 9db reference to.? Many import antennas make exagerated claims of gain, and your system is virtually useless as it is now. Go with the DB 224. You will be happy with the results. Andy --------------------------------------------------------- wrote in message ... Here is a problem that I'm having with my Diamond X700. Hopefully someone can give me some advice on which antenna would suit my needs best. Problem: My Diamond X700 cost me $400. I'm using it for a VHF repeater antenna. The problem it causes is every now and then, I get gurgling noises and crackling in the transmit and it takes out weak signals. This problem may stay in a few days and be gone for a few days and then come back again. It is not my TX RX duplexer. That was already checked out. I replaced my coax with LMR400. (75 ft. run) I have even changed repeaters and get the same results. Someone told me that the Diamond antennaes are NOT good in repeater service because they whip around and the rods inside do get broken and cause problems and will not show a bad SWR. My SWR is fine. Anyone out here have the same problems that I'm having? Do you have any suggestions on a proper antenna to use? I do have one suggestion and that was to get a Decibel products DB 224 antenna. Their website shows it as 6 DB gain where my Diamond is 9 DB. I'm afraid that I will lose my receive coverage with the lesser DB gain. Can anyone comment on the Decibel product? Any help and suggestions would be appreciated. Or if you can suggest any other antenna that could be used for repeater use at my home. |
#4
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![]() "Glenn Ziolkowski" wrote in message ... Amateur grade antennas do not have the mechanical durability to withstand typical repeater service. Likely what you have is wind-induced stress at some internal mechanical connections that manifests itself as the crackling noises. Have you ever taken apart a Station Master or Phelps Dodge commercial antenna? Neither one of them is internally very different from my $79.95 Workman brand knock-off of a Comet or Diamond. Antennas are antennas, whether they are being used for a police dept. repeater or seldom used amateur packet station. I agree on your assessment however. The culprit is either loose joints or water. I'd dismantle the thing and braze every union in place and then waterproof the casing joints with Seal Tight upon reassembly. |
#5
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Don't think you ever took one apart either. I have 4 of them running ,
there is NO COMPARISON to a "knock off". The station master (144 Mhz) is a 4 Inch Raydome , 26 foot long with 1/2" tubular dipoles that are brazed to a center 1/2 trans. It wiegh's almost 40 pounds and is rated for 90 MPH. It is also a DIRECT GROUND , unlike other claims like diamond / comet or workman which are DC ground through a capacitor that "blows apart" on strikes...Get your facts right... N4ATS Paul Vanasse wrote: "Glenn Ziolkowski" wrote in message ... Amateur grade antennas do not have the mechanical durability to withstand typical repeater service. Likely what you have is wind-induced stress at some internal mechanical connections that manifests itself as the crackling noises. Have you ever taken apart a Station Master or Phelps Dodge commercial antenna? Neither one of them is internally very different from my $79.95 Workman brand knock-off of a Comet or Diamond. Antennas are antennas, whether they are being used for a police dept. repeater or seldom used amateur packet station. I agree on your assessment however. The culprit is either loose joints or water. I'd dismantle the thing and braze every union in place and then waterproof the casing joints with Seal Tight upon reassembly. |
#6
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![]() Don't think you ever took one apart either. I have 4 of them running , there is NO COMPARISON to a "knock off". The station master (144 Mhz) is a 4 Inch Raydome , 26 foot long with 1/2" tubular dipoles that are brazed to a center 1/2 trans. It wiegh's almost 40 pounds and is rated for 90 MPH. It is also a DIRECT GROUND , unlike other claims like diamond / comet or workman which are DC ground through a capacitor that "blows apart" on strikes...Get your facts right... N4ATS Thanks for the (above) clarification, N4ATS. I was about to make the same comment to the original poster before you beat me to it. There is little physical comparison between top-notch commercially constructed antennas and ham stuff! Ed WB6SAT |
#7
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![]() "N4ATS" wrote in message news ![]() claims like diamond / comet or workman which are DC ground through a capacitor that "blows apart" on strikes...Get your facts right... OK Mr. Facts. Explain how does your commercial Station Master resonate "better" than any other amateur antenna? 1st off your direct ground means squat when it comes to VHF/UHF antenna performance, all it does is provide a lower resistance path for discharges (which is terrible for the radio unless all the grounds are tied together). On VHF/UHF a sealed brazed piece of #12 copper wire is just as durable as your 1/2" tubular aluminum (not to mention electrically superior). You must be one of those guys that actually believes that because an antenna is $500, it actually performs better................NOT. PS: My "knockoff" antenna has been servicing a repeater superbly for the past three years (its also on the highest communications tower in the state of RI). |
#8
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I had a friend who used the Diamond X700 antenna for a mountain top
repeater setup. He bought it because of its ruggedness. He had the very same complaints with it that you are having. He had to tear it down every few months and clean and resolder poor connections. He still uses it today as a remote base antenna - as you mentioned, it works fine in simplex configuration. I have since built 2 repeater systems and opted for the Comet GP-9 to test their performance. I was amazed at the results - not only have they performed well but they have been running mainenance free for over 4 years now. For the severe high wind/ice environments they make a non-conductive PVC type support arm that you can secure the middle of the antenna with. This obviously requires the Antenna to be mounted on a side-arm instead of at the top of the tower, I know of one in this configuration running succesfully with excellent results on a mountain top for quite some time. The Comet costs less than the Diamond as well. Mine were about $175.00. The Cell-Wave or Phelps Dodge or Folded Dipole type antennas are much more durable and obviously better built antennas but usually way more expensive. Unless you can score a used one cheap. Wade - KR7K ----- Original Message ----- From: Newsgroups: rec.radio.swap Sent: Friday, December 19, 2003 3:12 PM Subject: Help on Repeater Ant. To Buy Here is a problem that I'm having with my Diamond X700. Hopefully someone can give me some advice on which antenna would suit my needs best. Problem: My Diamond X700 cost me $400. I'm using it for a VHF repeater antenna. The problem it causes is every now and then, I get gurgling noises and crackling in the transmit and it takes out weak signals. This problem may stay in a few days and be gone for a few days and then come back again. It is not my TX RX duplexer. That was already checked out. I replaced my coax with LMR400. (75 ft. run) I have even changed repeaters and get the same results. Someone told me that the Diamond antennaes are NOT good in repeater service because they whip around and the rods inside do get broken and cause problems and will not show a bad SWR. My SWR is fine. Anyone out here have the same problems that I'm having? Do you have any suggestions on a proper antenna to use? I do have one suggestion and that was to get a Decibel products DB 224 antenna. Their website shows it as 6 DB gain where my Diamond is 9 DB. I'm afraid that I will lose my receive coverage with the lesser DB gain. Can anyone comment on the Decibel product? Any help and suggestions would be appreciated. Or if you can suggest any other antenna that could be used for repeater use at my home. |
#9
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No one said it resonates better. Hopeless to try to argue with you...You
obviously have no clue to what you are talking about...You win.... N4ATS Paul Vanasse wrote: "N4ATS" wrote in message news ![]() claims like diamond / comet or workman which are DC ground through a capacitor that "blows apart" on strikes...Get your facts right... OK Mr. Facts. Explain how does your commercial Station Master resonate "better" than any other amateur antenna? 1st off your direct ground means squat when it comes to VHF/UHF antenna performance, all it does is provide a lower resistance path for discharges (which is terrible for the radio unless all the grounds are tied together). On VHF/UHF a sealed brazed piece of #12 copper wire is just as durable as your 1/2" tubular aluminum (not to mention electrically superior). You must be one of those guys that actually believes that because an antenna is $500, it actually performs better................NOT. PS: My "knockoff" antenna has been servicing a repeater superbly for the past three years (its also on the highest communications tower in the state of RI). |
#10
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![]() No one said it resonates better. Hopeless to try to argue with you...You obviously have no clue to what you are talking about...You win.... .... don't sweat it. Just remember that someone has to be at the bottom of the Bell Curve. Ed WB6SAT |
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