Rohde & Schwarz ETL Broadcast Transmitter Analyzer - Page 1
Forum section: electronics / testgear

author: ocw
author_rank: Regular Contributor
timestamp: April 05, 2020, 04:39:43 am
content: I have been using a Rohde & Schwarz ETL broadcast transmitter analyzer lately and thought that I would provide pictures and displays from it. It can provide proof of performance measurements for both ATSC DTV and radio broadcast transmitters.I will provide the DTV screens in this message. The radio ones will follow in another message. All the DTV measurements provided are from a station about 45 miles away from myself, so some readings are compromised by noise and propagation. All were taken via the automated measurement process.The analyzer has worked well for me and provided me with a more enhanced capability of transmitter evaluation.

author: ocw
author_rank: Regular Contributor
timestamp: April 05, 2020, 04:46:41 am
content: Some of the radio parameter displays for the Rohde & Schwarz ETL broadcast transmitter analyzer are attached to this message.It is amazing the number of measurements that this analyzer can make. While I should be providing transmitter site measurements from an RF sample, the attached readings are from a combination of my “mono” HP 8648C RF generator and a local stereo FM broadcast station about 15 miles from me. Like the DTV measurements, the radio ones were taken via the unit’s automated measurement process. The broadcast station did not have the needed test tones from the analyzer and the microphone level audio from the analyzer was too weak for my RF generator. So, I just fed the generator’s 1,000 Hz tone to provide modulation. That makes most of the audio measurements meaningless. My goal to provide examples of some of the measurements that it can make, not to provide a specific transmitter’s evaluation.I corrected my HP8648C modulation problem and in my April 6th message below provide much better examples of the ETL's analysis of a FM signal.

author: Bicurico
author_rank: Super Contributor
timestamp: April 05, 2020, 10:14:49 am
content: Ebay lists these devices as second hand at 20.000 Euro!How much did you pay?Is it for hobby/TEA or real (paid) work?What are the spectrum analyser specs - especially max. span and frequency range?RegardsVitor

author: ocw
author_rank: Regular Contributor
timestamp: April 05, 2020, 01:47:57 pm
content: QuoteFew eBay listings have ETL's containing the radio analysis hardware that the unit which I am testing has. My employer purchased it new. I personally could only afford an EFA DTV analyzer (and other regular spectrum analyzers with better specifications).The ETL includes a 3 GHz spectrum analyzer with tracking generator. Its span can be increased to that entire range. For complete specifications see:https://scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/ETL_dat-sw_en_5213-7748-22_v2400.pdfI measured the harmonics of a DTV transmitter at the upper extreme of the ETL's frequency range down to at least -145 dBc without much special effort other than an added high pass filter.The ETL was ordered with the enhanced OCXO option, but not the GPS receiver. Attached are two screens showing it measuring the frequency of a GPSDO with an enhanced square wave output. Its harmonics at 990 and 2990 MHz were measured. It measured the 990 MHz harmonic 3.368 Hz low.The ETL might be an enhanced FSL3 spectrum analyzer. Its value is more due to its broadcast DTV, radio, QAM, etc. measurement capabilities, not its basic spectrum analyzer features.

author: ocw
author_rank: Regular Contributor
timestamp: April 06, 2020, 11:08:22 pm
content: Feeling a little embarrassed about the radio screens which I provided for the R&S ETL, I corrected the audio the audio problem to my HP 8648C RF generator and have a much better ETL FM signal analysis attached with this message.While the 8648C cannot provide a stereo FM output, I left the ETL expecting a stereo signal along with RDS and SCA data. Not actually sending that, the ETL identified a lot of problems on the signal. The lack of stereo also provided poor cross talk figures.But, look at some of the other data! Without any frequency correction on either, the ETL found the 8648C just 0.3 Hz off frequency. The frequency response, THD distortion and IMD were also excellent. Not a bad mono broadcast FM exciter.Besides all that was provided, there are a variety of other modulation and modulation density screens available on the main and subcarrier modulation. Plus, it can combine the frequency response of a high pass filter with harmonic and spurious signal measurements to provide a single diagram with a higher dynamic range shown.

author: brunomp
author_rank: Newbie
timestamp: March 07, 2023, 05:22:26 pm
content: hello my friend,i have one ETL like yours.you have a image of hdd?My ETL won't work...Can you help?thanks

author: Astralix
author_rank: Regular Contributor
timestamp: July 12, 2023, 12:08:58 pm
content: Hi!I have an ETL and watched the video from "The Signal Path" about the FSL frontend board. The hardware is very comparable. The ETL has the TG equipped and a few other components that were missing on the FSL version. It also does have different type numbers, but my board may be even an older revision too.Unfortunately, the video only roughly covers the different parts on the board and jumps quickly from the frontend input to the unlocked PLL. In addition the FSL board seems to have only one VCO, while the ETL board, even a nearly identical layout, has a few more VCOs installed. At least three more in the region between the Analyzer In and the TG Out port.R&S seems to upconvert the signal as the three VCOs cover 6,6 to 10.15GHz while the ETL works up to 3GHz. There are a lot of supply voltage filters and such, which I all measured good, but it would really help to have sort of a comparison chart for the supply voltages. I.e. I can only see that there are caps and 1R resistors and SMD filters that route 3V3 and 5V0 and some are 0V. But I am not sure if the 0V are correct or a missing supply line. In some places 0V seems logical as the chips have GND or Vss pins on the pads, but in some places, it might be a fault as the chips support positive and negative voltages instead of ground.On the right side of the board are two ICs which might be mixers, labeled 624 but I cannot find them. These have obviously two supply lines, each decoupled via a filter and a 1R resistor. But only one line has 5V the other is almost GND.Is that GND filtering to keep the chips' supply symmetrical or is there a missing voltage? As I said, the chip is not an HMC624 as it has less pins.There are a few other chips, like the ATMEL ATRRS02 for which I could not find any datasheet as well.Thanks for any ideas on how to get a clue of the board. I will try to follow the way in the video and borrowed some RF probes from the company over the weekend. But my equipment ends at 7GHz so I am not sure if I can trace out the 10GHz part on the front of the PCB.Astralix

author: Astralix
author_rank: Regular Contributor
timestamp: July 12, 2023, 12:42:30 pm
content: Before I forget: I found this part that looks a bit burnt. I could not really decode the letters completely.Looks like EA3AA and could be a voltage regulator?

author: analogRF
author_rank: Super Contributor
timestamp: October 29, 2023, 09:51:14 pm
content: Quote from: Astralix on July 12, 2023, 12:08:58 pmdid you fix your ETL? You never described what the problem was with the unit. Why did you have to open it up?that "2204" is most likely an RF switch and the two voltages toggle.in pretty much all spectrum analyzers, the first converter is always an upconverter to a fixed IF above the maximum input RF frequency.I think ETL also has a preselector filter or maybe it was an option

author: Astralix
author_rank: Regular Contributor
timestamp: October 30, 2023, 09:19:26 am
content: Hi!Unfortunately I still have no new information, so I was not able to proceed in repairing the board.I described the problem: it shows unlocked PLL.In my unit the PLL does not suffer from a dead cap but seems to work. I can see that some upconverting happens up to the range of 11 to 13GHz. But there are these ATRRS02 chips that get very very hot. But I cannot really check as they are probably custom chips designed by ATMEL specifically for R&S, hence ATRRS. No datasheet, no replacement chips.There is also this very burnt looking chip that I cannot identify:Regarding the ATRR02 chips, here they are, glowing at ~80°C.