Masthead A/B Combiner With Switchable Power-Pass on Both Legs
Product Code: BLACOM21AB
- Combines Group A & B signals
- Triple filtered to block 4G, 5G, and TETRA
- Weatherproof build
- Switchable power pass
Product Description
Masthead A/B Combiner With Switchable Power-Pass on Both Legs
Please Note: This product requires a power supply.
The BLACOM21AB is a high-performance A/B masthead combiner designed to merge TV signals from Group A (470–606MHz) and Group B (616–694MHz) transmitters. Triple filtered to minimise interference from TETRA, 4G, and 5G signals, it helps maintain clear and reliable reception.
This unit is ideal for use in areas where both Group A and Group B transmitters are needed. By combining signals from two aerials into one, it removes the need for multiple systems and allows access to a broader range of channels. It supports masthead amplifiers with a switchable power pass on both legs and offers low signal loss of just 2dB within each group.
Built for outdoor use, the housing features a weatherproof design with foam-sealed cable glands, a 90° wide-opening door, and an earth tag. F-type connectors ensure stable signal transmission, and the included mounting options support both mast and wall installation.
Features
- Combines Group A and Group B signals (470–606MHz and 616–694MHz)
- Triple filtered design to reduce TETRA, 4G, and 5G interference
- Switchable power pass on both legs for masthead amplifier support
- Low signal loss: Minimum 2dB across Group A and Group B frequencies
- High out-of-band rejection: 45dB attenuation above 702MHz
- Weatherproof enclosure with sealed glands and earth tag
- F-type connectors for secure and reliable connections
- Flexible mounting: Compatible with mast and wall installations
Applications
The BLACOM21AB is suited to installations in areas with overlapping transmitter coverage. It allows for a simplified setup using two aerials to receive a full range of TV channels across both groups. By combining signals into a single feed, it reduces equipment requirements and supports consistent reception in complex broadcast environments.
Technical Specification
Weight
0.25kg
14/08/2026
10/08/2026
Have to move the TV Ariel, and I found everything I needed in one place at a good price. Prompt delivery of items that are not commonly available. Highly recommend.
05/08/2026
No problems.
25/07/2026
Timely dispatch and tracking available. Reasonable prices too.
15/07/2026
Excellent! Great range of products. Website very easy to use. Fast dispatch. Extremely good communications. Thank you.
Google Company Reviews
10/08/2026
04/08/2026
03/08/2026
All received no issues
30/07/2026
Very courteous and helpful in dealing with my order error. A decent antenna delivered very quickly and I now have fm radio with a full strength signal.
25/07/2026
I had a bit of a struggle with their online ordering, I managed to raise an order as "collection" rather than delivery by courier. However Blake's went out of their way to fix the problem. Otherwise their on-line service produces a good transaction trail.

Good product, reasonable delivery time