Model BA-1-1000 is a 1:1 balun kit used to translate a 50 ohm
unbalanced input to 50 ohms unbalanced at power levels up to 1000 watts
PEP/100 watts continuous when used with a matched load. With a matched
load the SWR will not exceed 1.5 over the frequency range 1.8 to 61 MHz.
1,000 PEP watt rating on a 25% duty cycle. Will sustain about 100 watts RTTY or FT8 at 6 meters. (for higher power use the BA-1-1500 with 6-8 turns for higher frequencies).
Common mode impedance peaks
around 3,500 ohms at 10Mmhz.
With a matched 50 ohm load the SWR over the frequency range 1.8 to 61
MHz is shown in the following table measured with an AIM 4170 network
analyzer. Notice that the conversion from 50 to 50 ohms is very
consistent from 1.8-61 MHz and SWR is less than 1.3:1 over the range
allowing easy tuning by most radio internal antenna tuners or an
external tuner.
Ba-1-1000 1:1 Balun/Unun 1KW PEP 1-61 Mhz
The kit consists of a F140 ferrite toroidal core, enamel insulated
wire, a SO-239 connector with stainless steel hardware, and an
illustrated instruction manual with directions to connect the kit as a 1
to 1 balun/unun (unbalanced coax to unbalanced antenna or balanced
antenna like a dipole). Balun assembly time takes about an hour and is a
fun learning process.
Add a SO-239 Kit on output side to create a 1:1 unun (coax to coax line isolator) or add studs for a balun for use with dipole or beam antenna.
Use the recommwnded CB-Box-1 for a convenient enclosure.
A simple ferrite ring filter on the DC power line can help suppress the RFI noise affecting the victim device or keep the DC power cord from acting as an antenna and radiating RFI into other victim devices. This kit is also useful on laptop computer supplies, routers, cable modems, wireless phone charges, etc.
Installation is quick and easy: Just wrap the DC power cord through the center of the ring filter as many times as you can and reinstall. For best results with long DC power lines, use one at the ring filter at the wall wart end (to prevent the wall wart power supply from using the DC line as an antenna) and another at the DC plug end (to prevent the electronics in the powered device from using the DC power cord as an antenna). Typical installation is shown below:
The filter suppresses RFI in from .1-100 MHz. Inside diameter is 3/4 inch/19 mm.
Since most households and office environments have multiple wall warts we offer the Wall Wart RFI Filter kit in bulk quantity packages.
Known RFI Generators include Roku/Sling-TV power adapter - Interference heard in the AM broadcast band and harmonics. Also many ethernet Cable/DSL modems, cell phone chargers, computer power adapters have the same issue: using the AC or DC side of the power supply as a radiating antenna. RFI solution is to use a linear power supply, change adapters or wall wart ferrite filters