Ifr 1100s Service Manual
Reason for selling I'm closing my service shop. This IFR1100S is the military version AN/GRM-114A. Used on service bench only to service repeaters and duplexers, Comes with fully operational AC power supply and the MM-100E multimeter. No battery pack included. Spectrum Analyzer scope is like new and very bright. 100 kHz to 999.9999 mHz. Comes with manuals and instructions.
$1200.00 shipped and insured via ups-Ground Service to the lower 48 states. Sales is final, no returns, no returns. Seller: W4DON E-mail.
Philips lasermfd 6050 driver software. Dear all, Lately I picked up an IFR FM/AM 1100S but it looks to be affected by some troubles. I am not an expert of this instrument even though I am already owner of an IFR 1200S and I would like to know your impressions too.
I have summarized my first impressions regarding its troubles by means of four videos but the first fault I have seen when I turned up it is about the spectrum analyzer. I got the service manual from and I am currently studying where to put my hands to start to fix the spectrum analyzer issue.
Then I think to solve step-by-step the other faults or misalignments. If you want to help me, you can watch the videos and give me some repair tips. (poor RX, is it possible?) Kind Regards, auato. Yes Ariston, thanks for the hint.
It was the trimmer R30 on the Spectrum Analyzer board #2 (in the bottom side of the CRT). When I touched the trimmer by a screwdriver the trouble is definitely disappeard and does not appear anymore (however do you think is good idea to replace it)? Now proceeding the fixing I would like to watch the resistors on the ANT RX section Another thing. Please, could you tell me something about the strange behavior shown in the video? Attachments: 3.jpg 137.68 KiB Viewed 4744 times 2.jpg 124.41 KiB Viewed 4744 times 1.jpg 117.41 KiB Viewed 4744 times.
See the black trim pots with the yellow center? THEY ARE JUNK. That makes the 1100 pre 87. We threw over 30,000 of them in the trash to purge the inventory of them. They use a small piece of rubber to put tension on the wiper of the pot.
The rubber extrudes around the wiper and it looses tension and goes intermittent. I didn't watch the videos but There are 4 small signal diodes in the antenna circuit for static protection. If someone keyed into it, the diodes will be open. IIRC we used HP2800's, but about anything would work including 1N4148's.
Or maybe it's the other way around. We got a 500 in that had been connected to an outside antenna that took a direct lightning strike. There was a little stub of the coax still hooked to the antenna connector, and the entire front panel was black.
We flipped the thumbwheels one position, and figured what FM radio station it was tuned to. Thinking what the heck, I flipped it to battery and it came on and phase locked. Thinking what the heck, we pulled the melted coax off of the antenna connector and put a rubber duck on it. It worked grand. I guess Harold's diode bridge works for static after all. Thanks @ictjayhawk, @ariston, thank you all.
It's clear the vertical of SA depends on various junk pots.and I have also solved the 1kHz internal modulating which was missing or too low (see a previous video of mine) it was due to 1kHz frontal pot contacts (cold joints or dirty pot) but now this unlucky tool drives me crazy Now I am not able to hear the FM/AM broadcast stations anymore. I tried to review in my mind all things moved during the oscilloscope/S.A. Disassembling but I did those operations with a lot of care. OK, I should first check the circuit for static protection as @ictjayhawk & @ariston already wrote but I thought to connect, thanks to a BNC-wires adaptor, a small antenna directly into the connectors labeled 46 & 47 (1st local oscillator) for a short time to try to bypass the “Static discharge assembly' and the “Power termination assy' and I have not noticed any changes. Moreover, performing the 'mobile receiver performance evaluation procedures' it passes more or less all steps except the last ones (broadcast AM/FM audio receiver section). Attachments: IMAG0096.jpg 86.86 KiB Viewed 4689 times. Ok mates, thank you again.
Ifr 1100s Service Manual
I have not performed yet the @ictjayhawk's test because last days, before reading the @ictjayhawk's reply, I tried to perform some throubleshooting flowcharts following the service manual. Going deeply, I also found out, to my surprise, that also the generate function does not work anymore. So maybe the trouble involves a common part between RX and TX. When thumbweels are set all at 0, from T/R connector a signal @1.2GHz comes out, then with thumbweels at 100.000MHz, the output is 1.3GHz and so on. Done but no good news. No signal except for the 1st local oscillator. Do you think it could be the second mixer?
What happens if in the 1st mixer arrives only the signal from 1st local oscillator and nothing from second mixer? See this brief video: Moreover, in this video it seems to run well in generate mode and also dual tone generator and all circuitry before 1st/2nd mixer looks like that of a functional unit.
And why if I put the output from my handheld radio, the IFR1100's power meter runs well but I am not able to see the signal on the spectrum analyzer? Finally I undestood where the TX/RX problem was The culprit is a defective coax cable.
To be more precise, it is the cable to link the first mixer to the IF-1200MHz filter assy. The connector is widened and the connector was only rested over J10701 but without real contact. Now I have to change the connector or the entire coax. What are these kind of particular connectors and coax? I think RG316 for the coax pigtails. Next steps will be to check its performances.
Attachments: solved2.JPG 153.08 KiB Viewed 4564 times solved.JPG 45.27 KiB Viewed 4564 times. I kinda think 1st LO bleed-through is somewhat typical on the 1000/1100 but I could be wrong.
It has been awhile. The 1000/1100 RF attenuator is adjusting the level of the 120 MHz LO and not the output itself. The 500/1200/1500 all have the attenuator operating at output frequency after all the conversions, so every 10 dB step would also decrease any LO bleed-through as well. The output amp on the 500/1200 also rolls off real quick above 1 GHz and would help to reduce bleed-through as well. ETA: the 1000/1100 is a double conversion generator it takes the 120 MHz lo and multiplies it to 1200 MHz then mixes that with the 1200 to 2200 MHz LO then out the front panel to make the 0-1000 MHz Not much to stop the LO from coming through. The 500/1200/1500 is triple conversion.
It takes a 10.7 MHz lo and mixes it with the low loop to make an 90 MHz signal. That gets mixed with the 1210 MHz LO to make a 1300 Mhz signal that gets mixed with the 1300-2300 MHz LO to make the 0-1000 MHz signal. But then it goes to the output amp for leveling then the step attenuator so the 1st LO is attenuated quite a bit. So no LO bleed-through. But the 1000/1100 has a lower noise floor than the 500/1200 so the spurious LO signal isn't much of a concern. The 1500 is quieter than the 1100 despite being the same design as the 500/1200 but has a lot of extra electronics to remove the noise From noisiest to quietest: 1200 500 1000/1100 1500 The 1200 is noisier than the 500 cuz the cpu puts noise on the 5 volt supply and it gets into everything. Proceeding with a general check of the instrument I figured out why, in my opinion, the RX was poor and less sensitive and along with a little bit of noise in background than the 1200S's.
Actually it has not a poor RX but it is misaligned! For instance, to receive a good FM broadcast station transmitting locally at 103.000 MHz to hear a good and clear sound without noise I have to set my thumbwheels at 103.050 MHz, (50KHz up the correct value). Tried to take a look at the service manual to understand where to focus my attention to adjust the misalignment but thinking this manual as very dispersive and not easy to follow. I was thinking of focusing myself on the second local oscillator maybe slightly out of frequency. What do you think about?