SUPER CHOKER™ 4010 for 10-11-12-15-17-20-30-40 meters, 5KW
SUPER CHOKER™ 4010 for 10-11-12-15-17-20-30-40 meters
The Super Choker™ 4010 is our solution for frequencies from 7-30 MHz. Very
useful for operation on the 40-10 meter bands when you have connectors
already on the coax and works well with yagi, dipole, OCF (below the 4:1
or 6:1 matching balun), loop, and vertical antennas.
The Super-Choker™ 4010, when installed at the radio end of the coax, cuts down common mode current on your antenna feed line which has several benefits:
- Less induced antenna current on the exterior of the coax braid from your antenna reducing the “hot microphone” or rf feedback problems significantly
generated by electronic devices like computer, digital electronics that
is coupled to your coax shield as common mode current is significantly
reduced giving a lower ambient noise level on your receiver (less QRN). –
for better results use one Super Choker 4010 at the antenna and another
at the entrance to your radio shack. Noise level reduction of 1-6 “S”
units have been reported by many customers when using 2 Super Chokers.
- Less common mode current generally makes tuning your antenna easier as the outside cable shield is no longer part of the antenna. This effect usually cleans up antenna radiation patterns.
Super Choker™ 4010 uses three FT-240 ferrite toroids (with mixes chosen
to optimize choking impedance in the 40-10 meter frequency range) and
a RG-8/213 52 ohm coaxial cable pre-assembled for easy hookup to your
antenna feed line (just add two female barrel connectors). We
have measured choking impedance of 4.5K (centered near 14 MHz or 20
meters) – very effective for keeping the RF on your antenna across a
broad frequency spectrum. If you need higher choking impedance or a
compact choke for a beam, consider our CB-1-5000 5KW cube balun in a water proof NEMA® enclosure.
Typical choking impedance over the 40-10 meter frequency range is shown in the graph below:
For coaxial feed lines to your antenna, use one SUPER CHOKER™ at the antenna and another and the shack end. The choker at the antenna keeps the power fed through the coax on the antenna and the choker at the shack suppresses common mode current induced by your antenna radiation (and other sources of RFI from non-radio appliances from your house and neighbors).