Marconi Adret 742B RF signal generator - Page 1
Forum section: electronics / testgear

author: DoricLoon
author_rank: Contributor
timestamp: November 17, 2016, 11:11:57 pm
content: Hi I've just purchased a Marconi Adret 742B RF signal generator. Can't seem to find a manual for it anywhere. The best I've managed is a French version for the 740. The cheet sheet attached to the generator lists sweep parameters and their memory locations.Entering the first couple of sweep parameters start and stop frequency seems straight forward. The bit that has me foxed is how to set the "Frequency step and switching time by step" M92 in the case of band 1 sweep.Does anyone have an English manual for this generator or just keypress sequence instruction for setting sweep parameters?Thanks in advanceJim

author: Pinkus
author_rank: Frequent Contributor
timestamp: November 18, 2016, 05:20:02 pm
content: Yeah, it seems these Marconi generators are not very intuitive to use.I had one too (even older than yours) without a manual. Eventually I found one and kept it on my hard drive as I was to lazy to delete it (the Marconi was sold a few years ago).It is from a Marconi 2019A (80 Khz-1040 Mhz). Even this manual was hard to find a few years ago (maybe easy today .... or even harder).Please PM me with your mail adress if you are interested and I can send it to you. At least it might help to get an idea about what to enter where.

author: PA0PBZ
author_rank: Super Contributor
timestamp: November 18, 2016, 06:56:49 pm
content: Maybe you already found this, and it is only stating the obvious:http://midas.herts.ac.uk/helpsheets/signal%20generator.pdf

author: Gyro
author_rank: Super Contributor
timestamp: November 18, 2016, 09:04:34 pm
content: Sorry, can't help you with the 742. I have the original paper manual for my Adret 730A.... and yes, it is in French - I don't think they ever bothered to do English translations.

author: DoricLoon
author_rank: Contributor
timestamp: November 18, 2016, 10:52:37 pm
content: Quote from: Gyro on November 18, 2016, 09:04:34 pmThanks yeah i have the French operators manual for the 730 and 740. I also have the English version of the service manual for the 730 can send you it if you want?Quote from: PA0PBZ on November 18, 2016, 06:56:49 pmYeah I also have that, unfortunately it's about all I can find regards the 742B.However I have now figured out how to do sweepsFor anyone who needs to know.Enter frequency and amplitude for start frequency then key "M 9 0"Enter stop frequency key "M 9 1"Enter step frequency and then press the "FM" key enter step interval the key "M 9 2"To run the sweep key "SPL" "9 0"Hurray, works a treat. Only strange thing is, time is supposed to be mS and entering a max value of 1999 is stepping at more like 100mSThe FM key to allow entry of the time variable was the bit that foxed me. There is "step" below the FM key. All the other labels are above the keys. Therefore each time I pressed what I thought was the step key I was entering a modulation depth value.If anyone does stumble upon a manual, even in French I'd appreciate a copy.ThanksJim

author: Gyro
author_rank: Super Contributor
timestamp: November 19, 2016, 07:40:24 pm
content: QuoteLuckily I have a copy of the 730A service manual too (strange that should be in English but the User manual in French). Thanks for the offer though.Glad you got the sweeping figured out.

author: Fraser
author_rank: Super Contributor
timestamp: November 22, 2016, 09:08:07 pm
content: I own an ADRET 740A RF signal generator. Lovely hand built quality, but the data entry did seem a bit querkie when compared to my other signal generators.My unit came without user or maintenance manuals but I tracked them down in America and imported them. They were not cheap !I attach pictures of what I have.The 740A user manual is in English and the Maintenance manual has both French and English versions. I am fortunate to have the full set of schematics as well.Fraser

author: DoricLoon
author_rank: Contributor
timestamp: November 26, 2016, 06:18:18 pm
content: Hi Fraser,You don't have details of the place where you managed to track down the manuals do you? I have the French version for the 740. It's what I have used as a reference. I also have the schematics for the 740 which won't be perfect for my machine but if the need arises it's better than nothing.Next problem is to get Signal Hound SA44B and Adret 742B to track. Not so easy.

author: Mr Helpful
author_rank: Newbie
timestamp: January 09, 2018, 03:21:56 pm
content: Are you still looking for manuals?I may be able to help.

author: Fraser
author_rank: Super Contributor
timestamp: January 09, 2018, 03:54:20 pm
content: If anyone in the UK wants one of these signal generators I will be selling mine.PM me if interestedFraser

author: DoricLoon
author_rank: Contributor
timestamp: February 04, 2018, 09:57:19 pm
content: Quote from: Mr Helpful on January 09, 2018, 03:21:56 pmBetween the manuals for the 740 and some playing around I have it pretty well sussed out now but if you have an documentation for the 742B I'd be glad to have a copy.Thanks Jim

author: jhl620
author_rank: Newbie
timestamp: July 31, 2018, 10:44:09 am
content: I realize this topic hasn't been active, but I was hoping to find an answer about a Marconi / Adret 730A that I'm currently using, for which there doesn't appear to be a user manual anywhere that I can find. I did find the service manual, which is online but doesn't have the information I need. I'd love to get information about how to switch this instrument to remote control and the various IEEE488 (GPIB) codes. I saw that someone had posted a picture of a similar manual? Any chance to find out where you got it? Even the 740 manual might be helpful at this point! Thank you!

author: Gyro
author_rank: Super Contributor
timestamp: July 31, 2018, 12:15:01 pm
content: Welcome jhl620You can find the 730a manuals athttp://bama.edebris.com/manuals/adret/730aThey're a mixture of French and English as discussed earlier in the thread.

author: DoricLoon
author_rank: Contributor
timestamp: September 15, 2018, 07:16:56 pm
content: Quote from: jhl620 on July 31, 2018, 10:44:09 amThe link below should take you to my dropbox where I've uploaded a copy of the manual for the 730a. The manual includes instructions on remote access. That section is in French but those instructions and control strings are the same anyway.https://www.dropbox.com/s/s2dmqtun7o9vyls/adret_730a_vhf-generator.pdf?dl=0Below is a snip of code to ramp the frequency through steps from 1MHz to 500MHz in VBA with Visa. I'm no master coder so don't take it as gospel but example of the control strings are there.Code:Option ExplicitDim ioMgr As VisaComLib.ResourceManagerDim RFG As VisaComLib.FormattedIO488Dim AWG As VisaComLib.FormattedIO488Dim instrQuery As StringDim instrAddress As StringDim FRQ As IntegerPublic Sub Initialize_Click()On Error GoTo ioErrorSet ioMgr = New VisaComLib.ResourceManagerSet RFG = New VisaComLib.FormattedIO488Set RFG.IO = ioMgr.Open("GPIB0::1::INSTR")Exit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd SubPublic Sub cmdSetUP_Click()On Error GoTo ioErrorRFG.WriteString ("*RST")RFG.WriteString ("F 1e6")RFG.WriteString ("A-30")RFG.WriteString ("FM0")RFG.WriteString ("RF 1")MsgBox "RFG set to 1MHz -30dBm No FM modulation"Exit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd SubPublic Sub Ramp_Click()For FRQ = 1 To 500On Error GoTo ioErrorRFG.WriteString ("F " & FRQ & "e6")Application.Wait (Now + TimeValue("0:00:02"))Next FRQExit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd SubPublic Sub cmdReadIDN_Click()On Error GoTo ioErrorinstrQuery = AWG.ReadStringMsgBox instrQuery, , "Instrument responce to *IDN?"Exit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd SubPublic Sub instrclose_Click()On Error GoTo ioErrorRFG.IO.CloseMsgBox "Connection Closed"Exit SubioError:MsgBox "An IO error occured:" & vbCrLf & Err.DescriptionEnd Sub

author: Ankorjd
author_rank: Newbie
timestamp: May 06, 2019, 03:43:36 pm
content: Hello,The service manual for the ADRET 742 is uploaded in the KO4BB web site with 2 manuals (schematics and description of each module). What is missing are the schematics for the:- Output module 3- Attenuator control- Pulse modulation- Pulse driverIf some of you have these schematics we could have a complete service manualThanks in advanceAnkorjd

author: e_pigreco
author_rank: Newbie
timestamp: June 28, 2020, 04:03:28 pm
content: Hi,I know is a bit an old post, but it seems that also myself need help on the same Adret Signal Generator.I am replacing some tantalums which seem to have exploded but I need a full manual with schema all the schemas. As said by other people the downloadable version is missing some boards.Can someone help me to identify the values of the popped tantalums in the photo, just taken from my 742 device ?I already changed the C716 tant on the amplifier output board which was exploded and now I found also these tantalums exploded and I think this is the Attenuator board.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: June 28, 2020, 07:18:27 pm
content: HiI have the final printed copy of the Adret manual from Marconi. There is no schematics for the attenuator in it, it was very probably a factory exchange only item, just a parts list. All Tantalum capacitors used are either 16uf or 22uf at 16VDC. Suggest you up them all to a higher working voltage.Have you changed the Saft Nicad backup battery on the CPU card, they all leak and damage/destroy the CPU cardGeorge G6HIG in Dover UK.

author: PerArdua
author_rank: Regular Contributor
timestamp: December 05, 2022, 07:36:19 pm
content: Quote from: e_pigreco on June 28, 2020, 04:03:28 pmI've checked on my 742A and it is a 10uF, 25V tant. If you're (or anyone else) is around, could I ask for confirmation on the value/voltage rating of my blown resistor?Apologies for the necroposting, but I have a 742A which I suspect might be toast as there is some appalling soldering on this UHF board. Unfortunately no pics/schematics exist of this, and even worse I suspect the Adret 1226 modules (unobtanium) might be toast. Could anyone share a picture of their UHF boards please? In particular, looking to see if the trace (green circle) has been cut, and to determine whether the capacitor (orange circle) is original or not - I think I can see the remnants of a MLCC which drains away any further hope I have of easily repairing this.