Home Theater RFI Kit

MINI-CHOKER Coax Line Isolator, 500 Watts PEP, up to -38Db Common Mode Rejection, 1-61 MHz, 1:1 Unun

MC-1-500-50
$69.95
In stock
1
Product Details
Brand: Palomar Engineers
MPN: MC-1-500-50
Country/Region of Manufacture: United States
Effective Frequency Range (MHz): 1-60
PEP Power Rating (watts): 500 SSB (25% duty cycle), 250 Watts CW/FT8 (50% duty cycle)
Choking Impedance Range (ohms): 500-5000 (1-60 Mhz)
Common Mode Attenuation (db): 20-35db
Estimated Insertion Loss (db): .25 db
Input Connector Type: SO-239 female
Output Connector Connector Type: SO-239 female
Enclosure Size (LxWxH inches): 3" long, 2 in wide, 1.25" high

MINI-CHOKER(TM) Features:

- Uses proprietary Multi-Turn ferrite technology for maximum choking (up to -38 dB common mode noise rejection) and maximum bandwidth

- 500 Watts PEP, 50 ohm SO-239 connectors In/Out, 1-61 MHz (usable to 100 MHz) - AKA 1:1 UNUN

- Works for all coax fed antennas from 1.8-61 MHz (160-6 meters) - excellent for multi-band beams, verticals, dipoles, magnetic loops and highly unbalanced off center fed antennas.

- 2-5 times more common mode noise rejection, wider bandwidth and higher power then competing isolators

MINI-CHOKER feed line chokes are used to suppress common mode current carried on the outside of the coax braid which is often responsible for receiver noise and RFI in the receiver/transmitter. These chokes are very useful for suppressing RFI common mode current at the antenna feed point, at 1/2 wavelength intervals along the coax feed line and also at the entrance to the radio station.

This choke is available with a SO-239 input/output and ground/static bleeder stud (optional) for attachment to a ground rod. Use an isolator every 1/2 wavelength for the antenna operating frequency (include velocity factor in calculation). Use the ground lug option for long coax antenna feed lines (over 1/2 wavelength at the operating frequency of any antenna system in the near field of the coax).

For Higher Power needs use our MAXI-CHOKER 3KW version part# MC-1-3000 or 5KW version MC-1-5000.






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TECH NOTE: We also stock RFI kits to protect effected devices such as garage door openers, computers (laptops, desktops), dsl/cable routers, ethernet hubs and many more devices. If you run a high powered RF amplifier in your ham station also consider a linear amp RFI kit which will cut down RFI transmitted by your station. Remember there is always a “transmitter” and a “receiver” of RFI and the quest is to find and choke the “path” the RFI has selected – you need to add ferrites to both the transmitting side and the receiving side to eliminate RFI problems. The RFI-HTS kit only helps suppress RFI on the receiving side.

Typical RFI Problem/Solution:

Hello,
I am Larry, a ham operator and I am having interference issues with
my Direct TV system.
My station is a FT450D through an Ameritron ALS-600. From the amp
through a coax switch  to choose between an OCF dipole or an Hustler
5BTV vertical. Any power over 100 watts and my DTV goes off the air
and must completly reboot/format. Coax is RG-8. The DTV dish is
pointed away from the dipole and separated by about 25'. DTV was
totally useless! They suggested I not talk on the radio while she is
watching TV!  Please help me with a reasonable, cost effective
soultion. (The wife gets really pissed when I shutdown the tv!)

Thank you,

Larry 

 

Hi Larry,

Your RFI problem is quite common and is usually a sign of either a radiating coax feed line or reception of your radiated signal (source) by the Direct TV (the victim) through either the AC power lines acting as “antennas” for your ham signal or the coax braid of the satellite antenna acting as an antenna for your signal.

The solutions are straight forward:

1. To make sure your feed line is not radiating you need a feed line choke at each antenna feed point (also makes your antenna work better since it is not using the coax as part of the antenna).  You can use our simple Kit 110 with 5 snap on chokes on each antenna for this purpose.  Part # Kit 110 at $27.50 each – one for each antenna.  These chokes will keep your feed line from radiating and coupling into your ac power lines.  INFO HERE

2. The radiation from your antennas themselves may also be getting into the ac power lines and coax braid of the Direct TV antenna so you need to protect the victim receiver.  Depending upon the sophistication of your direct TV setup (e.g. home theater, dvd, tape player, sub woofer speakers, etc), the path of the RFI may be coming thru the AC power lines of any connected device to the video including the video monitor itself!  To help solve this problem we have a home theater RFI kit for up to 5 devices (you need a minimum of two – one for the Direct TV receiver(AC and coax input) and another for the video monitor AC power lines and HDMI or video input cable.  Our kit part # is RFI-HTS.  INFO HERE

These items should help reduce the RFI and let you operate on the air while your wife watches TV.

Bob Brehm, AK6R

Chief Engineer