Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
Any advantage to having a B&W balun on a yagi vs "6 coils of feedline?"
Reason I'm asking is that the B&W 5K I happen to have specifies "SWR less than 3:1". I know over almost any and every one of the five bands my new beam covers (10, 12, 15, 17 & 20M), it'll be higher than that at many points. I'm putting up a 7 element full size Mosley Pro 57B I got from W5KDG in Spring, TX a few months ago. What a job! It's going on a 50' Glen Martin HD aluminum "Hazer" tower. The hazer includes the Yaseu 1000 rotator and 8' mast for antennas, and cranks up from ground level. I also have a Cushcraft (6M, 2M & 440) beam at the top of the mast. (Mast reaching above the tower is about 4'). The Mosley will be 5-6" above the top of the tower to clear when turning. Probably have some interaction with the tower and guys being so close? Three 3/8" stainless steel guys are fastened at the very top of the tower and broken up with insulators. I figure the height will probably be the biggest factor for stronger signals. I'm now in the process of running five cables: 4 of RG/213 coax, plus one for the rotator, down a "messenger line" (also 3/8" stainless cable) from the hazer and into my shack. The coax lines are for the UHF, VHF and HF beams, plus an Alpha Delta DX-A: 1/4 wave slopers for 160, 80 & 40M. FWIW: 50' of coax X 4 is pretty heavy! For anyone's info: this is my "retirement project." Been licensed since 1957 while in high school, shortly after Sputnik was launched, but was busy raising a family, and never had the space for antennas like this. Also most neighbors here are horses which never complain. Hi! Marv W5MTV |
#2
![]() |
|||
|
|||
![]() "MTV" wrote in message ... Any advantage to having a B&W balun on a yagi vs "6 coils of feedline?" coiled feedline chokes are not as consistent over a wide frequency range as ferrite chokes. i don't know what is in the b&w balun, do you?? Reason I'm asking is that the B&W 5K I happen to have specifies "SWR less than 3:1". I know over almost any and every one of the five bands my new beam covers (10, 12, 15, 17 & 20M), it'll be higher than that at many points. i would expect a pro 57b to be well less than 3:1 across those bands.. |
#3
![]() |
|||
|
|||
![]()
Dave wrote:
Reason I'm asking is that the B&W 5K I happen to have specifies "SWR less than 3:1". I know over almost any and every one of the five bands my new beam covers (10, 12, 15, 17 & 20M), it'll be higher than that at many points. i would expect a pro 57b to be well less than 3:1 across those bands.. I would expect the 3:1 SWR limit is at the rated power. Reduce the power level and the balun will survive an SWR higher than 3:1. If it is rated 3:1 at 5 kW, hams shouldn't have a problem with a slightly higher SWR. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Tower project - Phase 2 Complete | Antenna | |||
AD5TH Tower Project Completed - Pics Online | Dx | |||
AD5TH Tower Project Completed - Pics Online | Dx | |||
AD5TH Tower Project Completed - Pics Online | Dx | |||
AD5TH Tower Project Completed - Pics Online | Antenna |