Teardown of a Ericsson radio base station, the RBS3202

[madsbarnkob]

All high resolution pictures and written information from the video can be found at my website: http://kaizerpowerelectronics.dk/teardown/ericsson-radio-base-station-rbs3202-teardown/

The RBS 3202 macro is an indoor Radio Base Station with one to four carriers and one to  six sectors at 20/40 Watt RF output power per carrier.

[technogeeky]

Another user and I commented about the ceramic elements you were discussing. As I said there, I've seen these in the oldest of the 20-30 cell phones I've torn down. I am pretty sure the name that describes the physical element is a ceramic coaxial resonator. However, it seems this describes a single unit of a circuit element, and it seems like every time I have seen these, they appear with several side by side (I've seen everything from 3 to 7 little parallel coaxial elements). However however: They always appear to be in some sort of staggered alignment instead of being a bank of parallel elements.

Since it's so easy to find pictures of individual coaxial elements, I wonder why it's so hard to find many examples of the staggered version of these units (again -- where the ends of the unit on on side do not all line up as they do in this solitary example I found on ebay).

So I think we can also reason that these can't be used for amplification, right? But what else can they be used for other than filtering? Can they be used as a delay line? What else?

[madsbarnkob]

It is filter attenuation, this manufacturer provide some simple math to calculate how many sections are needed for your specific application: http://www.lorch.com/ceramic2.html

For my next teardown, which is from the newer RBS6000 system, there are also a few new surprises like ceramic resonators in the diplexer, which properly has to do with the much higher frequency of a 4G system.

[technogeeky]

It is filter attenuation, this manufacturer provide some simple math to calculate how many sections are needed for your specific application: http://www.lorch.com/ceramic2.html

For my next teardown, which is from the newer RBS6000 system, there are also a few new surprises like ceramic resonators in the diplexer, which properly has to do with the much higher frequency of a 4G system.

Thanks!

My other questions:

1) What are the economics of these units, if you know (e.g. how much do they cost, how long do they run)
2) How are you getting ahold of them? Surplus? Are you a base station engineer?
3) If you are paying for them, about how much do they cost?
4) Do you intend to salvage parts from them, or are you just interested in them as a hobby, or are you just doing it for educational purposes? Scrap recycling?
5) Are they intentionally disabled/damaged in any way to prevent amateur use?

[madsbarnkob]

It is filter attenuation, this manufacturer provide some simple math to calculate how many sections are needed for your specific application: http://www.lorch.com/ceramic2.html

For my next teardown, which is from the newer RBS6000 system, there are also a few new surprises like ceramic resonators in the diplexer, which properly has to do with the much higher frequency of a 4G system.

Thanks!

My other questions:

1) What are the economics of these units, if you know (e.g. how much do they cost, how long do they run)

2) How are you getting ahold of them? Surplus? Are you a base station engineer?

3) If you are paying for them, about how much do they cost?

4) Do you intend to salvage parts from them, or are you just interested in them as a hobby, or are you just doing it for educational purposes? Scrap recycling?

5) Are they intentionally disabled/damaged in any way to prevent amateur use?

Answers:

1) They only last as long as they uphold the service to the market, so the more users that upgrade to 4G phones/subscriptions, they have to upgrade their networks. These units can f.ex. run 6 sectors (antennas) with 2 carriers on GSM, but moving up to 3G we are down to 3 sectors and for 4G its reduced to 1 sector. So if their tower is set up for 3 sectors, its cheaper to buy a whole new system than buying 2 additional "old" racks. GSM/3G gear seems to be in service for about 10 years, but newer systems seem to have even shorter service life.

2) I know a scrap yard owner that saves interesting stuff for me, this is properly the best way to get hold of old tech, get friends with people that has access to it I am not a base station engineer, I work in industry automation for offshore oil/gas platforms.

3) I return all parts sorted in metal/gold plated stuff and that is all he ask. Electronics scrap is a costly byproduct of scrapping, unless you have very large quantities, gold plated boards are of course a exception, but for the most part scrappers would only pay aluminium scrap price for a rack unit, as that is the main part of the weight (diplexer/heat sink/enclosures) Maybe even only buying it at iron price if it will take a lot of work to take apart.

4) I save some transistors, connectors and power supplies if they are in a working condition, sell them cheap to the HAM community, else about 90% is going back as scrap. I am only doing this for educational purpose, else they are just scrapped and gone forever, I am not a RF engineer, but I decided it was better to show what I could than nothing at all.

5) So far I have not seen any attempt on disabled units, some older units even comes with memory cards still in them, with all software/configuration available. I revealed a little bit of some software in http://kaizerpowerelectronics.dk/teardown/ericsson-rbs-2216-900-mhz-base-station-teardown/ but generally I am not interested in reverse engineering software / get in trouble for revealing such information, laws are rather strict around disrupting telephone communication, so I have no interest in assisting that.

[technogeeky]

Thanks very much for the detailed and honest answers. And thanks for sharing! I learned a lot in a few short videos.