Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
I am putting up my old TA-33SR by Mosley. I need to know how many windings
are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI |
#2
![]() |
|||
|
|||
![]() "Dan/W4NTI" wrote in message k.net... I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI =================================== Dan, I am unable to help you. Because, in common with most other people, I havn't the foggiest idea what a TA-33SR is. Questioners would do better by not depending on other people's imagination. It takes only a few seconds to provide a little more essential information. If you can't find the time then it can't matter very much anyway. ---- Reg. |
#3
![]() |
|||
|
|||
![]()
Dan:
Look he http://bama.edebris.com/manuals/mosley/ta33sr at the files: 00readme.txt (72 bytes) ta33sr.pdf (322 KB) John On Mon, 22 Aug 2005 21:59:28 +0000, Dan/W4NTI wrote: I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI |
#4
![]() |
|||
|
|||
![]()
I am putting up my old TA-33SR by Mosley. I need to know how many windings
are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI =================================== Dan, I am unable to help you. Because, in common with most other people, I havn't the foggiest idea what a TA-33SR is. Questioners would do better by not depending on other people's imagination. It takes only a few seconds to provide a little more essential information. If you can't find the time then it can't matter very much anyway. Reg, even to me (a relative newbie) "Mosley TA-33SR" provides all of the information needed to identify what Dan is talking about. A very brief Google identifies as a triband trap beam. I have little doubt that anyone who has ever owned one (and is thus likely to have the direct information that Dan is looking for) would recognize it from his description with no further description being required. Dan - since Mosely's manual doesn't mention such a choke, and the instruction sheet indicates a direct attachment of the coax to the driven-element feedpoint terminals, I doubt that the details of the choke are terribly critical. You could probably use any of the plans on the net for an air-wound coaxial choke-balun. One plan I see uses 18-21 feet of coax, close-wound solenoid-style on a 5" PVC form (stated to be good for 160-10 meters). Another site (http://www.bcdxc.org/balun_information.htm#Ed,%20WA2SRQ) has a table of air-core balun impedances, as a function of both frequency and construction (turn count and diameter). This chart suggests to me that 4 turns, 6 5/8" solenoid-wound might be a good option for you, as its impedance peaks at around the 15-meter band and is 500 ohms or better between 10 and 20 meters. Some folks seem to prefer solenoid-wound air baluns, others prefer scramble-wound. There seems to be a fair bit of disagreement as to which style works better, and why. The other choices are to use a different sort of balun (e.g. a W2DU ferrite-bead choke), or none at all. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#5
![]() |
|||
|
|||
![]() Dan/W4NTI wrote: I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI Hi Dan, The choke on a 3 band Yagi is to decrease feedline radiation, a choke balun. If you don't use a choke balun, you could have some pattern distortion, it would deviate from the classical 3 element Yagi pattern. I think the rule of thumb is have enough chocking impedance on the lowest band (20M) so that it is 10X the antenna impedance (50 ohm). You wind your coax into a coil that will accomplish this. The TA-33's that I have seen did not have the choke balun. In casual Amateur operation of the TA-33 I doubt you would miss the choke, or know if it was there or not. Gary N4AST |
#6
![]() |
|||
|
|||
![]() |
#7
![]() |
|||
|
|||
![]() "Dave Platt" wrote in message ... I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI =================================== Dan, I am unable to help you. Because, in common with most other people, I havn't the foggiest idea what a TA-33SR is. Questioners would do better by not depending on other people's imagination. It takes only a few seconds to provide a little more essential information. If you can't find the time then it can't matter very much anyway. Reg, even to me (a relative newbie) "Mosley TA-33SR" provides all of the information needed to identify what Dan is talking about. A very brief Google identifies as a triband trap beam. I have little doubt that anyone who has ever owned one (and is thus likely to have the direct information that Dan is looking for) would recognize it from his description with no further description being required. Dan - since Mosely's manual doesn't mention such a choke, and the instruction sheet indicates a direct attachment of the coax to the driven-element feedpoint terminals, I doubt that the details of the choke are terribly critical. You could probably use any of the plans on the net for an air-wound coaxial choke-balun. One plan I see uses 18-21 feet of coax, close-wound solenoid-style on a 5" PVC form (stated to be good for 160-10 meters). Another site (http://www.bcdxc.org/balun_information.htm#Ed,%20WA2SRQ) has a table of air-core balun impedances, as a function of both frequency and construction (turn count and diameter). This chart suggests to me that 4 turns, 6 5/8" solenoid-wound might be a good option for you, as its impedance peaks at around the 15-meter band and is 500 ohms or better between 10 and 20 meters. Some folks seem to prefer solenoid-wound air baluns, others prefer scramble-wound. There seems to be a fair bit of disagreement as to which style works better, and why. The other choices are to use a different sort of balun (e.g. a W2DU ferrite-bead choke), or none at all. -- Dave Platt ================================== Dave, having learned from you, a newbie, not from the enquirer, what a TA-33SR is, and having inspected the website you specify, I am a little wiser from reading the baffle-gab. I agree with your recomendations. Just get a hank of coax, suspend it in the feedline and away you go. But it may be more mechanically convenient and electrically better to wind a few turns of coax or Radio Shack twin speaker wire around a ferrite toroidal core. Or possibly do without a balun altogether. Try it and see what happens. It's so easy to do. ---- Reg. |
#8
![]() |
|||
|
|||
![]()
Dan/W4NTI wrote:
I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI My TA-33 manual calls for 5 turns at 6 inch diameter Bill, W3FI |
#9
![]() |
|||
|
|||
![]()
On Mon, 22 Aug 2005 21:18:30 -0400, BillJ wrote:
Dan/W4NTI wrote: I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI My TA-33 manual calls for 5 turns at 6 inch diameter Bill, W3FI That your TA-33 manual calls for a 5-turn 6" diameter balun fabbed from coax is welcome news, Bill, Mr. Mosely must have gotten religion lately. I had a 33 when they were first made available, but no balun was included. So I had a talk with Mr. Mosely (I've forgotten his first name) and asked him why no balun. He became irate when I admonished him for excluding the balun. He said his antennas were designed to not need a balun, and he admonished me for claiming they needed a balun to avoid pattern distortion due to unwanted radiation from the feedline. He kept that same erroneous viewpoint for as long as I know, until your manual now calls for a balun. Will wonders never cease! Walt, W2DU |
#10
![]() |
|||
|
|||
![]()
Mr. Moseley's first name was Carl. He was known on the air as "the Old Man
Himself." I worked him on 40 cw when I was a novice in 1967. He has probably been a silent key for 30 years or longer. I don't remember his call but I have his card in my card file. K4AVO Walter Maxwell wrote: On Mon, 22 Aug 2005 21:18:30 -0400, BillJ wrote: Dan/W4NTI wrote: I am putting up my old TA-33SR by Mosley. I need to know how many windings are needed on the choke. I seem to remember 6" diameter, but not the amount of windings. According to the manual there is no choke indicated at all. Anyone know anything about this? Dan/W4NTI My TA-33 manual calls for 5 turns at 6 inch diameter Bill, W3FI That your TA-33 manual calls for a 5-turn 6" diameter balun fabbed from coax is welcome news, Bill, Mr. Mosely must have gotten religion lately. I had a 33 when they were first made available, but no balun was included. So I had a talk with Mr. Mosely (I've forgotten his first name) and asked him why no balun. He became irate when I admonished him for excluding the balun. He said his antennas were designed to not need a balun, and he admonished me for claiming they needed a balun to avoid pattern distortion due to unwanted radiation from the feedline. He kept that same erroneous viewpoint for as long as I know, until your manual now calls for a balun. Will wonders never cease! Walt, W2DU |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
60 meter mod info needed... | Equipment | |||
Current in antenna loading coils controversy | Antenna | |||
Gotham Antenna info needed | Antenna | |||
102-E Western Electric Tube info needed | Boatanchors | |||
Vee Beam info needed | Antenna |