Only one XL Series filter needed per band for all station transceivers—plus other advantages
From the company that brought you the premium NC-1 Noise Canceling Bluetooth Boom Mic Headset and the Power Genius XL Amplifier, Antenna Tuners, and 8X2 Plus Antenna Switch for FlexRadios comes 4O3A XL Series High Power Band Pass Filters—today’s OnAllBands new product spotlight.
About 4O3A
Before we talk about the band pass filters—and there’s a lot to talk about—let’s look at the company behind them. The 4O3A call sign belongs to accomplished contester Ranko Boca, who earned his first license in 1980 and went on to participate in multiple World Radiosport Team Championships (WRTC). The 4O3A superstation is located on the Lustica peninsula at the entrance of the Bay of Kotor in southwestern Montenegro.
The team at 4O3A is known for designing and manufacturing high-quality products that help hams operate more efficiently and push contest scores higher.
4O3A XL Series High Power Band Pass Filters
XL Series filters come in models for 160/80/40/30/20/17/15/12/10/6M with either Type-N Female or UHF Female SO-239 connectors. They are intended for installation on the output side of a linear amplifier, filtering out harmonics as well as broadband noise from the power amplifier. The 160M and 80M models measure 24.4″ W x 5.9″ H x 5.9″ D (all other models are 4.3″ D).
Note: The 160M filter is a five-pole “low pass” filter, not band pass.
Typical applications include:
- Mitigating intra- and inter-station interference during contests
- Protecting receiver circuitry from damage
- Reducing RFI egress and ingress during everyday operations
- Enabling full duplex operation (transmitting and receiving simultaneously) on capable transceivers
The devices deliver high-power handling capability of up to 4,500W ICAS and high out-of-band rejection, typically >55 dB and sometimes as high as 75 dB on adjacent “contest” bands thanks to their five-pole filtering design.
For example, the 20M Series XL filter reduces transmitted and received signals on the 40M and 15M bands by approximately 55 dB or more with higher rejection figures on bands further removed from the primary band.
4O3A filters are capable of full legal limit power handling within a 3X safety margin that ensures stations fitted with a linear amplifier can safely place these filters between the linear amplifier and antenna.
4O3A Band Pass Filter Advantages
Filtering is inline after final amplification, allowing maximum reduction of transmitted broadband noise and harmonic energy.
Station signal routing and switching are easier compared to systems that use multiple low-power filters between transceivers and amplifiers in SO2R or multi-op setups. This translates into less complex and more reliable installations. Straightforward and uncomplicated signal routing systems cost less and will substantially offset an investment in a set of quality XL Series filters. Additional savings come from only needing one XL Series filter per band available to all station transceivers. Other band pass filter systems require a complete set of filters for each transceiver.
Other advantages include:
- Low Loss: The filters are designed for extreme (0.5 dB is typical) insertion loss to avoid overheating and power loss. Balance between each of the five poles of the filter is engineered using high-quality, high-voltage components to ensure long-term reliable and safe operation.
- Cooling: XL Series band pass filters come with 12VDC 40mA cooling fans standard at no extra cost.
- Mechanical Design: Robust components include silver-plated high-Q coils, high-current military grade capacitors, and heavy-duty aluminum enclosures with mounting flanges for secure installation on your bulkhead system or elsewhere in your shack.
- Filters are designed for maximum mechanical stability—an important feature since mechanically unstable coils often get deformed, which causes the filter to become detuned.
- Coils made from hard copper coated wire are a common mistake in filter design because they are elastic and easily deformed. XL Series coils are mechanically supported by three Teflon pillars that keep them mechanically stable. Additionally, each coil is made from special alloy copper tubes, custom created for 4O3A products. Coils are coated in silver to decrease losses.
- Simplicity: Contest stations operating in SO2R and multi-operator modes frequently have dedicated antenna systems for each HF contesting band. Installing 4O3A filters in the antenna line after the linear amplifier and antenna switch means the right filter will always be in circuit on the band/antenna combination in use. The operator never has to worry about switching filters between the transceiver and linear amplifier.
Note: XL Series band pass filters are hand-tuned, so there are small variances between units. Find 4O3A products and read more about 4O3A XL Series High Power Band Pass Filters at DXEngineering.com
