Johansson 6520 - 4 IF Channel Processor Review

Terrestrial digital processor

The Johansson - as you know - offer a range of solutions for all
the signal reception and distribution applications. an excellent
example processor 6520-4 selectively filters for converting
digital terrestrial frequencies.

The processor 6520 performs mutation four digital terrestrial frequencies in the UHF 470-790 MHz band (LTE Ready), using 4 selective SA W filters with a total gain 0-40 dB per filter, shelter zamak diecast. Also, the 6520 can be used as a super-selective single-channel filter if the used standard UHF filter is insufficient, e.g., due to a strong interference from a source LTE or interference from an adjacent channel.

Another use of 6520 is as an extension of an existing Profiler Plus or Super Profiler. Connecting the 6520 to the input of Aux Profiler, added to the system 4 SAW filters. Clearly, it is feasible and cascading more modules 6520, so that we can transform even more frequencies.

Physical Description - Connections

The extraordinary roof in 6520, has a UHF input on the upper side and lower side hosts the main exit, entry By Pass for another unit 6520 connection, and the entrance to the remote control 6565. Please note that the entrance to the remote control, supply voltage 12 V, thus the remote controller does not require external power. Finally, next to exits and find a connection for grounding the unit.

Programming

By 6565 the developer can adjust the parameters of 6520, very easily and quickly and without further feeding. To mention that this programmer can be used for 6620/6621/6622/6623/6630/6631 models.

The 6565 has a screen 2,7 "OLED 128x64 pixels, while the rotary selector, allows full operation with one hand.

By connecting the programmer, the latter is activated immediately after selecting "Start Scan" to find the device, then the Settings, we can either implement AutoInstall, or to adjust one by one the four frequencies. The application AutoInstall, detects all available channels and then select the change frequencies, while the manual method, directly regulate the new frequencies for channels of choice.

To mention that the Import to 6565 options and Export from 6565, we can copy the settings to another similar unit, saving you time.

Automatic balancing level - Adjust gain

So at each frequency setting, and the general setting at the end of the menu, we can apply the Auto Level function in order to have balance level for the 4 channels. The programmer starts the first channel and applies the appropriate gain, in order to have the same level and 4 multiplexes that we have selected for frequency conversion.

About gain, we have adjustable 0-30 dB in each multiplex, but massive adjustment eos -10 +10 dB, which means that for each multiplex, we can achieve gain up to 40 dB.

For any input signals entering the By Pass, we have -6 dB, so you should take care of their gain in the connected unit, eg profiler super or another 6520.

Channels 21,22,27,28 converted to 30,32,34,36 with automatic level equalization

Testing Setup

Under the test of 6520, we chose the channels 21,22,27 and 28 and converted to channels 30,32,34 and 36 with great success, both in conversion and implementation Auto Level, as you can see in corresponding photo with their range.

Our opinion

In 6520 the Johansson, is a very reliable and quality headend mutation four digital terrestrial frequencies, while programming becomes really simple with the controller 6565, without the need for external power.

Source: Digital Satellite News

Author: Periklis Pantoleon