To the venue owner – an ERRCS system is an expense with no ROI.

To the Emergency Responder – an ERRCS system is a MUST – with life safety for
responders, AND the public, depending on it.

Comba Telecom is committed to providing highly affordable,
state of the art solutions so venue owners can ensure
that First Responders get the coverage they need and deserve,
while making the cost to the venue owner as low as possible.


Comba's CriticalPoint Class A UHF BDA is a repeater solution that was designed with public safety first responders in mind. Fully compliant with the IFC and NFPA (National Fire Protection Association), CriticalPoint's UHF BDA supports frequencies 450MHz to 512MHz, up to 32 narrow-band filters and has the flexibility for supporting internal one or two window filtering. This unit will provide greater reliability and coverage for large building structures, tunnels, remote or rural areas and more. The channelized uplink squelch and channelized uplink AGC functions ensure minimum interference to base stations and optimizes communications quality.

It includes comprehensive alarming capabilities, which supports all NFPA and IFC required monitoring and alarming, and also provides local and SNMP based remote monitoring. The built-in signal generator and isolation testing function provide great convenience to system integrators during deployments.

In addition, by utilizing Comba's well-known high efficiency NEMA 4 amplifier design, the BDA provides a very small footprint, light weight design, low electrical operating costs, and low UPS backup costs. Comba's total vertical in house design and manufacturing capabilities, and supply chain management resources, ensures that the CriticalPoint UHF BDA is very affordable, reliable and state of the art.

Null Supports internal
one or two
window filtering
Null Supports
32 narrow-band
Null Uplink PA
Null Channelized
uplink (AGC)
Null Channelized uplink
squelch supported
Null Web based
GUI for
fast and easy
Null Built-in
isolation test to
prevent BDA
Null NFPA compliant dry
contact alarms,
NEMA 4 enclosure


Simplex (TX/RX)
Product Type
Part Number (AC Ver)
Part Number (DC Ver)
Class A (USA)
5W Simplex (TX/RX)

1 Window Passband
Product Type
Part Number (AC Ver)
Part Number (DC Ver)
Class A (USA)
2.0MHz in 450-470MHz or 1.0MHz in 470-512MHz
2.5MHz in 450-470MHz or 1.5MHz in 470-512MHz
Customized Passband

2 Window Passband
Product Type
Part Number (AC Ver)
Part Number (DC Ver)
Class A (USA)
2.0MHz in 450-470MHz + 1.0MHz
2.0MHz + 2.0MHz in 450-470MHz
1.0MHz + 1.0MHz in 470-512MHz
2.0/2.5MHz + 2.0/2.5MHz in 450-470MHz
2.0/2.5MHz + 2.0/2.5MHz in 450-470MHz
1.0/1.5MHz + 1.0/1.5MHz in 470-512MHz
Customized Passband

3 Window Passband
Product Type
Part Number (AC Ver)
Part Number (DC Ver)
Class A (USA)
Class A UHF BDA (AC) - 3 Window Basic Model

How can Comba offer so much for such a low price?
Comba is a prime manufacturer – we internally design and manufacture many sub components and sub assemblies that other OEMs outsource (PCBs, PCB insertion and wave soldering, metal chassis components, key passive components, power amplifiers, etc.).

This provides Comba with much lower cost – and in addition, internal manufacturing also allows us to maintain a higher level of quality control and better control over lead times.

How does Comba CriticalPoint have such low AC power consumption?
Comba utilizes High Efficiency Linear amplifier design – linear amplifiers draw significantly less operating current than conventional amplifier designs.

How does Comba CriticalPoint have such low weight?
This is another advantage of High Efficiency Linear amplifier design – extremely low weight. It is also important to note that since the Linear amplifiers generate less heat, there is no need for cooling fans – this also contributes to lower weight.

In addition, Comba's design team puts forth great efforts to ensure that there is no "over design" of any part of the CriticalPoint products, that could result in unnecessary extra weight or cost.

Does making adjustments to the CriticalPoint product require an onsite visit?
Not necessarily – if there is network access via modem or Ethernet available, the CriticalPoint BDA can be commissioned, adjusted, and monitored remotely. Modem/Ethernet access and SNMP v2/v3 are fully supported.

Is special battery back up equipment required for compliance with AHJ requirements?
No – CriticalPoint will work with any standard commercially available UPS or battery backup system.

Does CriticalPoint provide any built in oscillation protection?
Yes – CriticalPoint protects against oscillation in 2 ways:

First, there is a mandatory isolation test that must produce satisfactory results prior to being able to commission the BDA.

Secondly – in the event that something changes the isolation (and causes oscillation) while the BDA is in use, the CriticalPoint BDA will shut down and issue an alarm.

What is the warranty for the CriticalPoint BDA?
All Comba products have a 3 year product warranty.

What approvals or compliance ratings does the CriticalPoint product carry?
The CriticalPoint BDA is FCC, UL and IC approved – and it is fully NFPA and IFC compliant. In addition, the unit is housed in a NEMA 4X rated chassis.

Comba tests and certifies it's products through a Nationally Recognized Test Lab (NRTL) to meet the strict UL requirement standards. Click to view Comba's UL Standards Testing and Product Certification process pdf.

Does this BDA carry both analog and digital communications – and can it do so simultaneously?
As our specification sheet states – our BDA is compatible with and capable of passing analog and digital communications, and simultaneously.

How does this work: our BDA amplifies and passes RF (radio frequency) – RF can carry analog traffic, or it can carry digital packetized traffic. As stated, our BDA is simply amplifying and passing the RF - we do not read, manipulate, or modify, nor really even "see" or know, what the traffic content is.

A way to look at this: consider the BDA and the antenna infrastructure as plumbing in a home or building – all the plumbing does is carry water. The water can be hot water or cold water - or could be potable or non-potable water – the plumbing doesn't care. And in a similar fashion, our BDA does not care what the traffic content over the RF is comprised of.

So how can analog and digital, which are different, be carried simultaneously? The end devices (base station and mobile devices) operate on either analog or digital – meaning that an analog device won't even see the digital traffic, and the digital devices won't even see the analog traffic. So – both types can be mixed over the same RF path with no chance of one interfering with the other.

How can I commission the Public Safety CriticalPoint BDA on a P25 radio system which is non-trunked (no control channels available)?
Comba Public Safety BDAs utilize control channel signal levels in P25 based trunked system networks as the means for monitoring and alarming for donor antenna malfunctions. It is rare – but there are cases where the network is NOT a trunked network; therefore, there are no control channels available for use in donor antenna monitoring and alarming. In these cases – Comba offers an easy to install/easy to use kit that includes all of the components necessary to provide the ability to monitor and alarm for donor antenna malfunction in non-trunked network applications.

These kits are available directly from Comba – following is a link to the specification sheet for the kit; the specification sheet also includes the part number and other information necessary to order the kit. Link: BIAS-T KIT FOR NON-TRUNKED RADIO SYSTEMS

CriticalPoint's BDA software report function doesn't work in a Chrome browser.
Solution: Download PDFs in Chrome

1. On your computer, open Chrome.
2. At the top right, click More Settings.
3. At the bottom, click Advanced.
4. Under "Privacy and security," click Content settings.
5. Near the bottom, click PDF documents.
6. Turn on Download PDF files instead of automatically opening them in Chrome.

Chrome will now download the generated Report.


Questions? Call 1-408-649-2638 or email This email address is being protected from spambots. You need JavaScript enabled to view it.

Need a UHF BDA Quote? Log into our Portal and fill out the UHF BDA Form to determine the UHF configuration for your project. UHF BDA Online Request Fom