#31 IFR 1200 Service monitor problems and repairs 

Thanks for sharing that. This is the type of success stories I like to hear. Had the exact same thing with the resistor on another unit. I also will be doing another repair very soon on a super S. Thanks for the comment

Thank you Jay

Thanks for watching Eric

Thank you Kim for that kind comments. I only use common sense approach to my repairs.

+DENNIS N Thanks Dennis. I hope so too. man these are a pain to work on.

Thanks for that very nice comment

+FEY Clean switches make everyone happy. I am just glad they designed them to be servable. I think the KW 520 will be my next video. Should be fun. Thanks for the comment and the wish, same back to you my friend..73

+Dino Papas Hi Dino, good to see you. Man I bet that cost a nice penny. I know just a basic cal was high dollar back in the day. The 1500 is a nice unit.Thanks for watching and sharing that story my friend73

+orbiter8 (John) John you are so right. They are built like a tank. I will say the worse part of the unit is the cabling. So many cables lol. But you know they are like a classic old car in a way. Glad you like the tour and repair of it. Thanks my friend for stopping by.

They still are. You should see the front panels of the newer instruments; they are machined from solid aluminium, and I know the people who do it.

+Gary g1fsh Thanks Gary. The IFR series were great units. First one I ever saw is when the owner of the local EF John dealer came out to work on radios in our company trucks. I was impressed with it. I went to work for a GE land mobile radio dealer and we used WaveTek test sets there. After many years I went to work as a service tech for the same EF Johnson guy I mentioned. This is where I fell in love with the IFR stuff. We had a 500 and 1200. We sent the 1200 out for repair and the bill was close to 3 grand. Yikes. Thanks again and glad you enjoyed it.

Thanks

Thank you very much for the kind words. At times you have to dive in with both feet. I am going to do a complete rebuild on one of these units soon.

Especially with the blue double-clad PCB's... They are very fragile....

Hi, I am working on doing just that. I am also implementing using it in my repairs explaining how to set it up for a particular task.

Thanks for the nice comment. Some of the boards have a bit of varnish on them. And they run hot. I would pull the scope boards and power supply boards and make sure there are no discolored components to be on the safe side.

I still have not repaired this part of It is a 40/10 ohm unit.the unit. Interested in knowing what type of terminator you had at the time. The ones for the IFR are not standard 50 ohm.

+Jeff Wallach Thanks Jeff for the wonderful comment. There is just not enough information out there on these units so I try and share as much as I can on them. A lot of folks are just scared to crack one open and poke around. But if there is information available this helps and wish others would share. Thanks again commenting and stopping by. I will try and post more as time goes on.73Buddy

+The Radio Shop Thanks! My latest challenge is a bad FOCUS on the scope....nice, bright trace, but over the past few years the FOCUS has been going out...have to check the Service Manual to figure out if it is a bad capacitor...probably a well known issue....Jeff

+Jeff Wallach Yes that is from a bad cap. Also check the resistors in that circuit. If cracks it will put a carbon burn onto the pcb. The supply board is directly under the crt. When checking the caps look for high ESR.

+The Radio Shop ..Wonderful, thanks for the tip and heads up...is that are difficult to get to>?

+Jeff Wallach Not at all. Just be careful removing the case. Easy to snap a coax connector off. Remove the 4 knobs on the scope control and the two knobs on volts/division. Then remove the nuts. There are two thumb screws inside just under the crt. You will see the plate directly under the crt. Once the 2 screws are loose you can them lift the crt and board assemblies out to remove cables.

+DextersLab2013 I searched for a similar switch but have not found one as of yet. Afraid they were custom parts just for these units. At least they are a bit serviceable, And as long as the spring contacts are good one may could etch a new wafer... Thanks for stopping in my friend.

+John Cunningham Thanks John. Yes a very nice piece of gear. Just wish I had the tracking gen option. Still need to order the $200 termination pad then it will be complete once again. Although it works just fine as it is. Glad you enjoyed the repair.

If the job is not complete you would not be happy. You and I take great pride in our test equipment by maintaining it in like new condition. How many technicians would tackle a wafer switch that are synced so precisely, "not many" they would replace the mechanism if the option were available. That is true craftsmanship.

Steve, Thanks for the tip on those blue boards. They are very easy to destroy. I love these old units. Wish I could add a tracking generator to mine. But with the price they want to install I can buy a stand alone unit with more features. Would come in handy for duplexer tuning. Wish more folks would post information on repairing these units. That would really help folks that have set them aside when they quit. But seems those that know are quiet lol.Thanks again for posting. Buddy

+raccoonnyc Thank you for your kind words. Award eh? he he. Very delicate work. Just coat the entire area in flux, reflow fresh solder, use my 25 year old de-soldering sucker to remove as much as possible, then heat with hot air till the switch falls right off. Made that sound easy huh? Problem is these boards are getting a lot of age on them. Does not take much to rip a trace or via right out. Thanks again my friend and glad you liked it.

+Mr Carlson's Lab Thanks for the kind words Paul :) And yes, I am bit finicky about  certain made radios. And you are right about that resistor. Most expensive one I ever seen. I have searched for 2 years trying to come up with something cheaper. Nada, I am trying to vision you signal gen, model number? I am sure I have seen it with that vast amount of gear you have. going to have to go back and search your vids... like to see the schematic and layout to compare with. Anyway I am off till Monday so looking at what is next on my list to video. Thinking about a good ole boat anchor. TS-520 perhaps? And as always I am going to throw you or Peter in there somewhere;) Thanks again and looking forward to your next one also.

Thanks Buddy! I Vote for Peter! :^) The signal generator is a Polarad SMPC. The R/S SMPD service manual crosses. The file is almost 400MB large (part 1) easily found on line. On my bench, it's located on the upper half towards the curve tracer, right below the grey spectrum analyzer I look forward to what ever you choose to fix and do a video on. The TS-520 is a nice mix of technology, solid state and tube at the same time. I have been working on an in-depth video for months (In my spare time) hopefully it will be done soon.

+Mr Carlson's Lab Will check it out Paul, Thanks. I love test gear.. That is a large file lol. Cool, the 520 and HP volt meter are next on the list :) Cant wait to see that video you mentioned. Have a good one my friend.

+The Radio Shop Looking forward to what ever you record!!

+TRXBench Well, I recorded 2 videos this week end. Problem is I am very sick and the voice sounds terrible. Going to try and edit them tonight and get them posted. In the mean time I see you have uploaded. Going to watch.

Thanks

+MikesRadioRepair .CBRadio Great suggestion Mike. You cannot beat that stuff. In fact I need to order more. I use it on all my boat anchor rigs like band switches. Thanks for bring this to our attention. I bet that recap was a job.

+The Radio Shop A job to say the least. The one huge advantage of the Stabilock chassis design is its very easy to pull all the modules. Basically each module just slides in the back and is retained by two thumb screws. The modules each contain two or more PCBs. Its a pain because there are just so many caps in it. Whats worse was the caps are almost all low profile and there is really no room to use one that's close in size. Its either the correct physical size or it just isn't going to fit. Ended up ordering most all of them because most of what I stock was to large. Made sure I got the best money could buy long life low esr caps because I don't ever want to have to do it again. Hopefully they will be good for at least another 25 to 30 years. Get started on your HP VTVM yet? Mike

+MikesRadioRepair .CBRadio I hate it when modern day components don't fit.. At least you should be good to go for a while.The TS-520 and the HP are next. maybe this week end.

Thanks, that is what it is all about.

deoxit is great stuff. no problems at all with using it on those. I would apply it with a q-tip to avoid the wafer from soaking up the chemical.

+TRXBench Hi Peter. Always good to see you my friend. Guess our test equipment is getting old like ourselves :" I been looking at buying a third unit. Glad you like the video and thanks for joining in my friend.

Thank you

+wb8cxo Hi Mike. Thanks for your comment. Yes anytime you send one of these out it cost way to much. I agree with your calibration comment as a hobbyist. You are right about a good calibration video being put on RU-vid. Perhaps one day I will do that. I will be doing more on this. I do not have a reference stand frequency in my shop. I use WWV as my standard. Cannot get much better than that as a hobbyist. I believe it was Alan w2aew that posted a video on how to set a frequency counter zero beat with WWV. Will have to look that one up again. Thanks again Mile and glad you enjoyed the video.

+wb8cxo I just checked. It is Alans video #58ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-QCJ4cQGOQLI.html

Thanks D. I have this bad problem of saying single when I mean signal.

+mikep95133 Thanks. It is a bit of work if you have to. As far as monitoring the signal plug a cable into tone out or Demod out, then plug into scope in. You can now see the audio component of the signal when you switch it to scope mode. Hope that helps.

+The Radio Shop Is there a way to monitor the rf signal on the 1200s?

+mikep95133 Not in the sense that you are thinking about no. As in looking at the raw carrier. It has a audio demodulator built in but the only RF carrier is what you see in the spectrum. I may be wrong, but don't think it is possible with an outside source and using the scopes input.

+The Radio Shop I think you are right. I'll dig up an rf tap when I can. Thanks for all of your time!

+mikep95133 Alan w2aew did a nice video on monitoring your ham transmitter with an oscilloscope. Simple circuit you can build and works great. Thanks for the comments.ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-y4Zt_LJX1Tc.html

Hi. I wish there was such a forum. Seems those that know do not share information. I sort of have to learn as I go on it.

Hi, in the service manual it tells you how to set the hi loop and low loop lock unit. One is probably off and needs a bit of adjustment. If that does not take care of the problem then the PLL is unlocked. Follow this link below and see if that takes care of the problem

www.kgelectronics.com/kg_electronics_new_beta2p_011.htm

If you go to KG electronics you will find the procedure to tune the lock.

UPDATE - I had a bad varistor under the shields of the low lock board. I temporarily replaced it with a 4004 diode, and the MV209 is on its way for a proper repair. Any chance you can show us how well (or poor) the receiver is throughout it's spectrum? Or a video on using the 1200 to tune a receiver? Thanks!

Thanks

Agreed!

The 1200 is just a plain version with S/A and no tracking gen, the S has tracking gen option. Never seen a 1299a, that one is new to me. The Super S has a bit more memory, different scope/power supply lay out.

1200 had some limited features. 1200S can be upgraded for a tracking generator, not sure about the A,. Super S had tracking generator as standard.

Open it up with power removed. Pull cables and replace. This helps many times in just reseating the cables.

There's another video showing an IFR doing the very same thing as mine and it turned out to be a varactor diode in the Low Loop Filter. I've got one on order so hopefully that'll solve the problem.

Yes you do have to remove the circuit boards because the screws that hold the IF Block go thru the middle chassis and into the IF Block housing. If you guage from underneath you can tell which ones to remove and how many there are. I watched another tech remove all of them and carefully lay them one on top the other. I would not do that. There are enough cables to replace as it is without making more work for yourself !!! And for anyone interested, the company that made those 40 ohm and 10 ohm termiation resistors for the IFR1200 is no longer in business. And, the location is listed as a "super fund cleanup site" !!! Wow ! Buddy''s replacement idea with the 39 ohm and 10 ohm resistors is a great one. Just to make sure I NEVER have to replace my resistor again (once was enough at $200) I always sink my transmitters into a Heathkit Cantenna and tap off the RCA jack for a small signal output to the IFR.

Craig, never saw your reply, did you ever get this fixed?

No never went any further Any help would be great

+Paul Kleinpeter Happy dreams Paul,. It is off to work I go...

Funny but never saw this question. Did you ever get yours repaired?

Please do. I like to hear his comments also. And any information he would like to share on the IRF's. Thanks

I am looking forward to the response. I like my ifr1200. I want to fix it. 73

Thanks. I think you are having a blast watching these videos. I better make more soon or you will run out. This is about all I do is watch RU-vid videos. I do not watch TV. Lots of folks are scared to take these apart. But as you know it is simple. As far as donation I accept PayPal if you like to donate. Click the "show more" tab under a video and follow the link labeled "Contact Info". That will take you to my web site. Thanks for watching my friend.

Okay just sent it to your Earthlink account (listed on your website) at PayPal. Cheers!

Thank you very much for your donation!

+S Robins Thanks Sue. And thanks for stopping by. Really appreciate the tip.

+oHIo VooDoo Thanks friend. Glad you like it. :) Now I have to get busy and upload some more....

Yep, not much room in there for anything else.