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Search found 2035 matches

by kcbooboo
Tue May 28, 2019 2:13 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550 - Channel Down key progged as Zone Toggle???
Replies: 19
Views: 1817

Re: CDM1550 - Channel Down key progged as Zone Toggle???

I pulled apart, to clean, dozens of CDMs. I took the entire molded plastic control head "housing" to the kitchen sink. As I recall, the circuit board had the display clipped to it. You don't want to remove the LCD assembly because the zebra strips require careful alignment to insure it all...
by kcbooboo
Mon May 27, 2019 4:24 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550 - Channel Down key progged as Zone Toggle???
Replies: 19
Views: 1817

Re: CDM1550 - Channel Down key progged as Zone Toggle???

You can remove the knob first, but it's easier to do after you've removed the circuit board. It has some outward-spreading clips that hold it into the hole in the front panel, and these can easily be compressed from inside if you need to remove the knob. So ignore the knob for now, pry the head off ...
by kcbooboo
Sat May 25, 2019 12:24 pm
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550 - Channel Down key progged as Zone Toggle???
Replies: 19
Views: 1817

Re: CDM1550 - Channel Down key progged as Zone Toggle???

The control head can easily be taken all apart with nothing more than a plastic prying tool or a small flat-blade screwdriver. After that, clean the carbon trace contacts on the front of the pcb, clean the silicone button assembly and all the plastic parts. I usually wash them in hot water and some ...
by kcbooboo
Fri May 24, 2019 9:20 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550 - Channel Down key progged as Zone Toggle???
Replies: 19
Views: 1817

Re: CDM1550 - Channel Down key progged as Zone Toggle???

Perhaps the control head is dirty or bad? All the pb switches generate two analog voltages based on "row" and "column". Take the control head apart, make sure the pcb contacts under the silicone buttons is clean. Someone could have poured soda or coffee into the radio. Try anothe...
by kcbooboo
Mon May 06, 2019 2:41 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: MSF5000 Schematics and codes help please
Replies: 3
Views: 1879

Re: MSF5000 Schematics and codes help please

"Can anyone please direct me to a place?" http://www.repeater-builder.com

"Any ideas?" VCOs failing to lock. Check the electrolytic capacitors on the Uniboard. There's an article on the above web site.

Bob M.
by kcbooboo
Wed Apr 10, 2019 5:11 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2014D/0900HS muddled display
Replies: 3
Views: 137

Re: R2014D/0900HS muddled display

Most of the data in the R2001 series is sent around as binary-coded, over four or eight lines. I immediately noticed that the "4" bit is stuck in one position, since 0,1,2,3 display correctly but 4,5,6,7 show up at 0,1,2,3. In binary, 3 = 00100011, 7 = 00100111, so the 00000100 bit seems t...
by kcbooboo
Thu Dec 20, 2018 8:03 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Micor repeater model B84RCB3106AT questions
Replies: 15
Views: 662

Re: Micor repeater model B84RCB3106AT questions

Sometimes a local microphone will key the station and include PL/DPL along with it, whereas an XMIT button or slide switch may only key the station with no modulation at all. If there's a PL/DPL encode board in the control tray then the output of that should be checked to verify that it's putting ou...
by kcbooboo
Fri Dec 14, 2018 3:39 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Micor repeater model B84RCB3106AT questions
Replies: 15
Views: 662

Re: Micor repeater model B84RCB3106AT questions

Don't give up so quickly. The MICOR seems overly complicated at times but you can force it to do what YOU want by making modifications to the backplane and plug-in cards. Lots of people are running MICORs with CW ID that comes out with PL/DPL. There are multiple audio inputs and multiple PTT inputs;...
by kcbooboo
Thu Dec 13, 2018 9:40 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Micor repeater model B84RCB3106AT questions
Replies: 15
Views: 662

Re: Micor repeater model B84RCB3106AT questions

Most Motorola base/repeater stations do NOT transmit PL/DPL when doing a CW ID, at least if it's being generated by the internal logic or controller. It's designed that way on purpose. You will need to connect an external CW ID differently if you want the PL/DPL to be transmitted when the CW ID fire...
by kcbooboo
Thu Nov 01, 2018 4:30 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?
Replies: 9
Views: 3426

Re: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?

Open the radio and check the HLN numbers on the RF and PA boards. They're either on small white stickers or stamped in ink on the board. Then you won't have to "guess" any more. Once you determine what band the radio really is supposed to be on, blank it and reinitialize it. TX Power norma...
by kcbooboo
Sun Oct 21, 2018 5:02 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?
Replies: 9
Views: 3426

Re: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?

Correction to the above post: The first letter is "H"; the second letter is "L".

Bob M.
by kcbooboo
Sun Oct 21, 2018 3:29 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?
Replies: 9
Views: 3426

Re: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?

Low-band MaxTracs are only rated for 60 watts RF output. If you crank it all the way up, the power control circuit DC output will be sensed by the cpu as being too high and it will do exactly what you are seeing: TX briefly then cut off. If the radio has been modified or is operating out of band, th...
by kcbooboo
Sat Oct 13, 2018 5:50 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?
Replies: 9
Views: 3426

Re: Maxtrac Low Band 31 MHz - TX power falls back after PTT pressed?

The data signal when you release the PTT could be "post-MDC". It sounds like you need to completely reprogram the radio. Check the "SL" steering-line test point on the RF board and verify that it's between 2 and 7.6VDC on both RX and TX. You may need to adjust the TX VCO coil if ...
by kcbooboo
Sat Sep 22, 2018 5:12 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM 750 and cdm1250 wont power up.
Replies: 12
Views: 2207

Re: CDM 750 and cdm1250 wont power up.

They probably say "Not Field Replaceable" just because of the component density, surface-mount technology, and just not easy to replace with a 40w soldering iron "in the field". Those radios are pretty much "replace the entire board" if there are any problems. There's m...
by kcbooboo
Tue Aug 21, 2018 3:40 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2410 Random Shutdown?
Replies: 5
Views: 624

Re: Motorola R2410 Random Shutdown?

Electrolytic capacitors that are over 20 years old are always suspect. Tantalum capacitors are known for shorting out - even intermittently. Usually a piece of equipment will have dozens if not hundreds of those. For some reason 10uF tantalums are very common and seem to fail the most. Hopefully one...
by kcbooboo
Thu Aug 02, 2018 3:31 am
Forum: Test Equipment & RF Equipment Alignment
Topic: motorola r2001a frequency counter it does not work
Replies: 4
Views: 610

Re: motorola r2001a frequency counter it does not work

Once you've set the operating frequency correctly on the screen, the carrier frequency ERROR, of an RF signal applied to the RF IN/OUT N-female jack, can be viewed on the MONitor display along with deviation. To use the frequency COUNTER, you need to feed the signal into the separate Vert/Sinad/DVM/...
by kcbooboo
Thu May 31, 2018 3:34 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1250 TX / RX issues
Replies: 3
Views: 861

Re: CDM1250 TX / RX issues

Also could be a defective mini-UHF female connector. The inner contact gets spread open by improperly crimped or soldered male connectors plugged into them, and fails to make a connection. Acts as a capacitor. Sometimes another cable will work fine. The only cure is to replace the mini-UHF female co...
by kcbooboo
Mon Mar 12, 2018 5:13 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: MSF5000 power control test mode
Replies: 6
Views: 1026

Re: MSF5000 power control test mode

You probably can't fix anything on the ceramic IPA substrate but the surrounding discrete parts might be easy to replace. The style of IPA/REG in that manual is the "old" type. The newer ones use a small RF brick and the majority of the circuit board is the regulator and an interface to th...
by kcbooboo
Tue Feb 27, 2018 4:02 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: MSF5000 power control test mode
Replies: 6
Views: 1026

Re: MSF5000 power control test mode

Did you find the problem?

Bob M.
by kcbooboo
Tue Feb 20, 2018 9:04 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: MSF5000 power control test mode
Replies: 6
Views: 1026

Re: MSF5000 power control test mode

Additional info: find 6881082E20 in the Motorola MSF section and open the VHF IPA and Regulator PDF file. It has troubleshooting procedures for both assemblies. The test procedure even documents how to put the station into tSt mode. The pot could go open. That's often how they fail. The arm doesn't ...
by kcbooboo
Tue Feb 20, 2018 8:01 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: MSF5000 power control test mode
Replies: 6
Views: 1026

Re: MSF5000 power control test mode

1. Sorry. It is documented, although very hard to find, in some manuals, and that IS the procedure to enter power control bypass test mode. In the Motorola MSF section of repeater-builder, search for 6881082E05 and go to PDF page 26. 2. No. The power control circuit, which includes the front panel p...
by kcbooboo
Wed Jan 10, 2018 4:48 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Spectra 146-174 110w capacitors
Replies: 21
Views: 2770

Re: Spectra 146-174 110w capacitors

The 2nd oscillator in the Spectra RF board is a phase-locked-loop design. There's one and only one potentiometer inside those radios and it adjusts the PLL frequency. The pots can go bad/open, and the oscillator dies or is way off frequency so you receive nothing. Play with that pot a bit. Also read...
by kcbooboo
Tue Jan 02, 2018 5:15 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Spectra 146-174 110w capacitors
Replies: 21
Views: 2770

Re: Spectra 146-174 110w capacitors

If you go to www.repeater-builder.com, Motorola area, Spectra section, "Radio and Equipment Modification Articles", you will find the 2nd, 3rd, and 4th items to be rather pertinent. In particular you should avail yourself of the recap offers made by AI4JI in the 4th link.

Bob M.
by kcbooboo
Mon Dec 18, 2017 7:58 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: MSF5000 UHF PA interchange
Replies: 6
Views: 960

Re: MSF5000 UHF PA interchange

You can thank Motorola for being so consistent in their cable labelling color codes. That's bitten more than one user.

Bob M.
by kcbooboo
Tue Dec 12, 2017 5:33 am
Forum: Test Equipment & RF Equipment Alignment
Topic: COM-120B Power Supply polarity of the capacitors !!
Replies: 4
Views: 947

Re: COM-120B Power Supply polarity of the capacitors !!

Usually there's a white or silver line along the side that marks the negative lead of the cap. In the photo, this line wraps over the top of the cap and is on the side opposite from those yellow connectors. If this is a power supply board, there are probably negative power supplies where the positiv...
by kcbooboo
Wed Nov 08, 2017 5:05 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2001D/2008D/2009D etc, Power Meter Calibration
Replies: 4
Views: 960

Re: R2001D/2008D/2009D etc, Power Meter Calibration

On the A/B/C units, the dummy load, and hence the RF sampling circuit, are all inside the RF input module (A11) where the step attenuator resides. As this is a very well shielded and sealed module, it's not something that can be readily adjusted in the field. The mfgr had test jigs for such assembli...
by kcbooboo
Wed Nov 08, 2017 4:56 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Convert a Henry Amp to do simplex
Replies: 12
Views: 1354

Re: Convert a Henry Amp to do simplex

The 100w amps can have a DPDT relay installed inside, but a 200w amp might be a bit too much power for that kind of setup. The relay will take some number of milliseconds to activate when its circuit senses RF, and the amplifier itself may start putting out power before or while the relay switches. ...
by kcbooboo
Sun Sep 03, 2017 4:55 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Typical Exciter Output for Base Station and Repeaters
Replies: 4
Views: 1092

Re: Typical Exciter Output for Base Station and Repeaters

I don't know. As the Quantro uses an MSF5000's PA which needs 2-4 watts, there could be an IPA module in the Quantar chassis that amplifies the raw exciter to the level required by the MSF5000 PA. I have no documentation on the Quantro, just the Quantar.

Bob M.
by kcbooboo
Fri Sep 01, 2017 2:26 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Typical Exciter Output for Base Station and Repeaters
Replies: 4
Views: 1092

Re: Typical Exciter Output for Base Station and Repeaters

Add VHF-Lo as a column for the Micor only. Micors tend to send 400-600 milliwatts to the PA. MSR2000 is probably the same as the Micor but I didn't research it. MSF5000, VHF-Hi, UHF (403-474), 800, 900 IPA output is 2-4 watts. MTR2000 and MTR3000 exciter both output +14 dBm or about 30 milliwatts. Q...
by kcbooboo
Thu Aug 24, 2017 4:13 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Syntor X9000, always in Carrier Squelch?
Replies: 11
Views: 1261

Re: Syntor X9000, always in Carrier Squelch?

Motorola has used several methods at the mobile microphone to enable coded squelch: The button on the back of the mike... 1. must make contact with chassis ground (a metal clip screwed to a metal chassis). 2. must make contact with a larger metallic outer ring around it (a metal clip that doesn't ne...
by kcbooboo
Sun Aug 13, 2017 4:55 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: Maratrac continuous duty transmit power?
Replies: 9
Views: 1299

Re: Maratrac continuous duty transmit power?

The case is cast metal of some kind, probably aluminum or an alloy. Welding could be difficult. Easier to mill it flat and bolt on a decent-sized finned heat sink.

Interfacing the radio as a repeater transmitter is quite easy. I bet there's at least one article on the web that deals with it.

Bob M.
by kcbooboo
Thu Aug 10, 2017 3:43 pm
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550s without heads - can they be used for a repeater?
Replies: 8
Views: 1320

Re: CDM1550s without heads - can they be used for a repeater?

According to the service manual, the radio CAN be programmed to turn on and off with IGNITION voltage and it CAN ignore the ON/OFF switch on the volume control. But you have to be careful when playing with that programming because you could get the radio in a state where it can't be turned on with e...
by kcbooboo
Thu Aug 10, 2017 3:28 pm
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

Bernie found some letters on one connector. They appear to be Omni-Spectra "OMQ" series, which have not been made since the late 70s, early 80s. There may not be anything that will actually fit properly these days.

Bob M.
by kcbooboo
Thu Aug 10, 2017 4:43 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

Thanks. It looks bigger than SMB but smaller than SMA. Also could be reverse-polarity.

I presume they used the same extender kit on the entire R2001 line, however it's not inconceivable that they used something else on the "D", where so much changed.

Bob M.
by kcbooboo
Wed Aug 09, 2017 8:03 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

Does DPJ126 or Jry or anyone else know what type of RF connectors were used on the RF boards and motherboard? I'd like to make some RF extender cables so I can align the boards above the chassis. I already have 72-pin and 100-pin extender cards. They look like SMA without the threaded outer part or ...
by kcbooboo
Fri Aug 04, 2017 4:36 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550s without heads - can they be used for a repeater?
Replies: 8
Views: 1320

Re: CDM1550s without heads - can they be used for a repeater?

Not sure if the radio requires the control head to pass self-tests.

Probably safer to pull the flex cable out of the radio and leave it attached to the control head.

Bob M.
by kcbooboo
Fri Aug 04, 2017 4:34 am
Forum: General Motorola Solutions & Legacy Radio Discussion
Topic: CDM1550 - switchable 3dB pad - does this exist?
Replies: 4
Views: 816

Re: CDM1550 - switchable 3dB pad - does this exist?

Could it be a per-channel "Local/DX" setting, like GM300s have?

Bob M.
by kcbooboo
Thu Jul 27, 2017 8:25 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

I connected the CRT to the CR70 tester per the book, using pin 4 (focus) as G2. I got ZERO emission. I then tried it with pin 7 (accelerator) as G2; still zero emission. I went through the rejuvenate, auto restore, and both manual restore procedures. Still had zero emission using pin 4, but when I h...
by kcbooboo
Fri Jul 21, 2017 9:22 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

One more quick question. I know the CRT pins for filament, cathode, and control grid, but I'm not sure which is the correct pin or element to use as the second grid, or G2. The Sencore CR70 setup manual says pin 4 which is the Focus grid, but other research has indicated that the Focus, Geometry, an...
by kcbooboo
Fri Jul 21, 2017 1:48 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

There are vertical and horizontal gain pots on the A2 card that control the overall CRT display. These are separate from the vertical and horizontal calibration pots that are on the A3 or front panel cards. Obviously noise coming through the RF section will raise the baseline. You might have to disc...
by kcbooboo
Tue Jul 18, 2017 11:58 am
Forum: Test Equipment & RF Equipment Alignment
Topic: Motorola R2001A
Replies: 34
Views: 4189

Re: Motorola R2001A

Lynn: I realize it's been a while, but things go slow here. My CRT is still quite dim. A friend had one in the same condition so he bought a rather used (and needing repair) Sencore CR70 CRT tester/rejuvenator. He ran his CRT on that and after a few rejuv cycles, he said it looks like a brand new tu...
by kcbooboo
Sat May 06, 2017 12:28 pm
Forum: Radio Programming
Topic: CDM750 TX Alignment?
Replies: 3
Views: 1144

Re: CDM750 TX Alignment?

Yes, there's a separate program called TUNER that does all the alignments.

If the programming software is newer than a few years, remember that it only allows narrow-band (2.5 kHz) programming unless you've got the special entitlement key to allow 5 kHz deviation.

Bob M.
by kcbooboo
Sun Apr 16, 2017 5:16 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2001C/HS will not power up.
Replies: 16
Views: 1976

Re: R2001C/HS will not power up.

The supply takes incoming 120VAC and reduces it through a transformer and the four stud diodes to create "RAW DC" that's in the 12-16V range. The incoming 12VDC line joins up at this point. Then they use the RAW DC to run a 20 kHz oscillator and some switching transistors that feed a secon...
by kcbooboo
Fri Apr 07, 2017 5:55 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Removing wires from MTR2000 wireline block
Replies: 9
Views: 1205

Re: Removing wires from MTR2000 wireline block

Easy is a relative term. Pull the wireline card, pull the station control/exciter/receiver modules, unplug some connectors, cut some ty-wraps, remove the screws holding the rear cover on, remove any remaining screws holding the backplane to the chassis. If this was my station, I'd do all of that. I ...
by kcbooboo
Wed Apr 05, 2017 6:29 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2100 LVPS differences
Replies: 6
Views: 1127

Re: R2100 LVPS differences

The A2 card in the "A" is an RTC4007A. The "B" and "C" use an RTC4007B. So they "might" be interchangeable. Bernie would probably know for sure.

Are you sure the "U" isn't a "D" or some other letter?

Bob M.
by kcbooboo
Tue Apr 04, 2017 12:01 pm
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Removing wires from MTR2000 wireline block
Replies: 9
Views: 1205

Re: Removing wires from MTR2000 wireline block

Well, I CAN tilt the plastic blocks up and down, it's just not possible to grab it to get both edges to come out at the same time, because the opening in the metal plate over the backplane just isn't big enough to put anything in to wedge it out. Nothing inside the rectangular holes seems to move ei...
by kcbooboo
Sun Apr 02, 2017 10:20 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2100 LVPS differences
Replies: 6
Views: 1127

Re: R2100 LVPS differences

The B and C LVPS are the same. I believe the A is quite different but still modular, while the D is totally different.

Bob M.
by kcbooboo
Tue Mar 28, 2017 3:02 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2001C/HS will not power up.
Replies: 16
Views: 1976

Re: R2001C/HS will not power up.

They use Schottky diodes in the 12V supply and the readings are different from ordinary silicon or germanium diodes. I think with my Fluke 189 DMM in diode mode I got around 0.35V drop on three and 0.1V drop on the fourth, and I replaced the fourth one. The new one also had 0.1V drop, so I didn't kn...
by kcbooboo
Mon Mar 27, 2017 6:58 am
Forum: Base Stations, Repeaters, General Infrastructure
Topic: Removing wires from MTR2000 wireline block
Replies: 9
Views: 1205

Re: Removing wires from MTR2000 wireline block

Well, I yanked and wiggled and the plastic block just does not want to come off. Now it could be that the remnants of the wires I snipped are holding it in place, as the insulation is larger than the holes the wires go through. I'll have to snip them right at the plastic block. Do I first have to re...
by kcbooboo
Mon Mar 27, 2017 4:35 am
Forum: Test Equipment & RF Equipment Alignment
Topic: R2001C/HS will not power up.
Replies: 16
Views: 1976

Re: R2001C/HS will not power up.

Try powering it up with 12VDC. Those units take the incoming 120VAC and run it through a transformer and rectifiers to come up with 12VDC that's used by the rest of the supply. Could be bad diodes or filter caps in the 120VAC to 12VDC part of the supply. You may eventually want to, or need to, repla...

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