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.

Comba utilizes High Efficiency Linear amplifier design – linear amplifiers draw significantly less operating current than conventional amplifier designs.

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.

No – the CriticalPoint single band BDAs include a license to switch from one single band to the alternate single band. No additional purchases are required.

Not necessarily – if there is network access via modem or Ethernet available, the CriticalPoint BDA upgrade license can be installed remotely.

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.

No – CriticalPoint will work with any standard commercially available UPS or battery backup system.

Yes – you can allocate channels to each band in any increment (example:  40 channels in 700MHz and 56 channels in 800MHz) but you cannot deploy more than 64 channels in a single band and the total number of channels cannot exceed 96.

The CriticalPoint BDA provides 2W of downlink power for EACH BAND independently.

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.

All Comba products have a 3 year product warranty with advanced exchange service.

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.

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.

In certain cases when deploying a Class A BDA in a P25 Phase I/II network environment, the typical 12.5KHz or 25KHz channel bandwidths with their higher level of group delay may cause some issues with call quality and clarity. A channel bandwidth of 12.5KHz may result in group delay figures of up to 35usec; 25KHz channel bandwidths may result in group delay figures of up to 27usec – either of which can cause call quality issues as mentioned above.

To minimize or eliminate any call quality issues resulting from using these very narrow channel bandwidths, Comba has released updated firmware for our Class A BDA devices that allows for channel bandwidths of 75KHz. Utilizing a 75KHz channel bandwidth will result in group delay figure of 15usec maximum – which is well within the tolerances required for excellent call quality on P25 Phase II networks. This updated firmware is available directly from Comba and is available on Comba’s portal which you can access here: Firmware Download

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

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.