Portable Operation RFI Kits

Off Center Fed (OCF) antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center. For example, the Palomar Engineers 4010 OCF is a very popular antenna and consists of an off center fed dipole with sides of 55 feet and 11 feet and it will work all bands from 40-6 meters.The End Fed OCF uses the same dimensions but the wire section is 55 feet as in the OCF and the coax outer braid is used for the “other” short side of the OCF dipole. We place a choke on the coax at the 12 foot distance from the matching unit and we essentially have an OCF antenna with its great frequency range, but with only a 55 foot wire length instead of the 66 feet required by the regular OCF. You feed the antenna from one end which may be more convenient for some installations. This antenna will work on 40-30-20-17-15-12-10 and 6 meters. Most bands are under 3:1 SWR and easily tuned by your transceiver’s internal antenna tuner or external tuner used with an amplifier. (see BULLET-4006 for specific details and SWR curves).

These antennas are MUCH BETTER PERFORMERS than End Fed Half Wave antennas because they work the WARC bands, DO NOT HAVE A DANGEROUS HIGH VOLTAGE at the antenna connection and are SHORTER to fit in smaller spaces yet provide more band coverage up to 6 meters!

Portable operation is fun but also brings challenges to the radio operator concerning receiver “noise” levels, RF interference from adjacent sources including close by transmitting stations, and RFI from portable generators.  A typical scenario and some suggested Palomar product solutions are shown in the picture below:

Generator RFI testimonial:

Bob 

Received your order in a timely fashion. Tried the generator kit on Sunday & it drops the noise from S9 to S5 and 
took out all the electrical noise.  I may want some more toroids from you at some point for other interference problems
I have  here.
Ken VE3KCY

Using an amplifier?  Don’t forget our Linear Amplifier RFI Kits

Want to make up your own RFI kits for a particular operation? Here are links to some of  typical RFI solutions used in portable operations:

AC/DC common mode filters

Feed Line chokes

Coax Noise Filters

If you use a computer for logging in your portable operations, RFI getting into computers will often lock up your computer and/or radio and a computer RFI suppression kits may be helpful

Computer RFI Kits

Make your expedition or portable operation a pleasant and fun outing and remember to take along your RFI kits so you have more time to operate rather then to troubleshoot intermittent or noisy receiver conditions.

Portable Antenna Kits

If you need an effective portable antenna which folds up for transport yet is easy to deploy at your operating site, consider the BULLET series of end fed wire antennas.

BULLET Antennas (click on link or picture for more info)

Bullet Antenna Product 300x292 - Portable Operation RFI Kits