PDA

View Full Version : IC-2100 Low output power



K2LRV
04-02-2009, 04:14 PM
I picked up an IC2100 2m rig with low output power at a club auction for $20. I pulled the RF-power module cover off thinking it may be a cracked somewhere (I guess this is common for the SC-1091). I cannot see any cracks, and have perfect continuity when tested with a DVM.

Any other simple test I can perform with a DVM to track the problem? There is a PIN Diode located right after the output, but I don't think they can be tested with a dvm...

K8ERV
04-02-2009, 04:37 PM
There may be an adjustment that is wrong or faulty. I can send the service manual if you need it. I have 6 of these rigs.

TOM K8ERV Montrose Colo

K2LRV
04-02-2009, 04:38 PM
There may be an adjustment that is wrong or faulty. I can send the service manual if you need it. I have 6 of these rigs.

TOM K8ERV Montrose Colo

A Service manual would be great k2lrv at me dot com

K8ERV
04-02-2009, 10:16 PM
Sent to your listed arr-l addy.

TOM K8ERV Montrose Colo

KM5QF
04-02-2009, 10:51 PM
tom, may i please have one too?
ive got two of the rigs and one has at least a bad PA.
RF parts wants 80 bucks for the module.
anyone know anywhere a little cheaper?

thanks

K7JEM
04-02-2009, 11:22 PM
tom, may i please have one too?
ive got two of the rigs and one has at least a bad PA.
RF parts wants 80 bucks for the module.
anyone know anywhere a little cheaper?

thanks

You could substitute a SAV7 if you added a 3 dB pad to the input. Your power out would drop to 25 watts, but the module is only $40.

Joe

K8ERV
04-03-2009, 01:13 AM
tom, may i please have one too?
ive got two of the rigs and one has at least a bad PA.
RF parts wants 80 bucks for the module.
anyone know anywhere a little cheaper?

thanks

U got it. I also sent it to JEM by mistake. No extra charge.

TOM K8ERV Montrose Colo

KM5QF
04-03-2009, 01:47 AM
thanks tom, got it.

K7JEM
04-03-2009, 02:39 AM
U got it. I also sent it to JEM by mistake. No extra charge.

TOM K8ERV Montrose Colo

I wondered what that was. Figured someone sending me an infected file, was afraid to open it.

Now that I know what it is, I will look at it.

Joe

K2LRV
04-03-2009, 01:06 PM
Thanks for the files...

So I have determined that it is not the 1091 module. I have an IC-207H with an problem with the speaker output, so it is also apart on my bench, so I toke the module out of that one and placed it in the 2100... still no output...

Looks like more testing to do...

WB3BEL
04-03-2009, 04:51 PM
I am assuming that the receiver is working fine. If so you can rule out a lot of the obvious and common failure modes like broken RF connectors or solder joint.

I guess that you have determined that its not the PA module. When you try to transmit does the rig draw significantly more power from the supply? It should.

You can measure PIN diode with multimeter. Treat it like its a normal diode. This is not 100% electrical test but it will find blown diodes. MAybe not the leaky ones, but that is more of a problem on RX. A leaky diode on TX still usually will pass TX power through. Measure the voltages in TX and RX modes.

If you determine later that it is the PA module. You have to look very carefully at the ceramic substrate of the module. Pop the plastic cover off and put it under a microscope and using a strong light look to see if there are some really teeny cracks that propagate through the microstrip traces. This is a very common failure mode. If there are one or two they are usually in the chokes that feed power to the RF transistors. If you have a steady hand and a good microscope, you can repair these by bridging the broken trace with small gauge wire and soldering with a fine tip iron. I find that wirewrap wire or equivalent is pretty good for this.

K2LRV
04-03-2009, 05:04 PM
I am assuming that the receiver is working fine. If so you can rule out a lot of the obvious and common failure modes like broken RF connectors or solder joint.

I guess that you have determined that its not the PA module. When you try to transmit does the rig draw significantly more power from the supply? It should.

You can measure PIN diode with multimeter. Treat it like its a normal diode. This is not 100% electrical test but it will find blown diodes. MAybe not the leaky ones, but that is more of a problem on RX. A leaky diode on TX still usually will pass TX power through. Measure the voltages in TX and RX modes.

If you determine later that it is the PA module. You have to look very carefully at the ceramic substrate of the module. Pop the plastic cover off and put it under a microscope and using a strong light look to see if there are some really teeny cracks that propagate through the microstrip traces. This is a very common failure mode. If there are one or two they are usually in the chokes that feed power to the RF transistors. If you have a steady hand and a good microscope, you can repair these by bridging the broken trace with small gauge wire and soldering with a fine tip iron. I find that wirewrap wire or equivalent is pretty good for this.

Well I have inspected the PA module, and like I said I swapped a known good one into it briefly. I read somewhere that it could be the APC circuitry, but I have to dig into it more this weekend.

RX works fine, just no output power...

KM5QF
04-03-2009, 05:18 PM
at least i know mines an easy fix, although at a cost almost equal to what the rig is worth.

just connecting the pwr leads it draws 6 amps

K2LRV
04-03-2009, 06:24 PM
Decided to sell it as is along with the 207h... see my add...

KK0G
04-03-2009, 08:42 PM
If you determine later that it is the PA module. You have to look very carefully at the ceramic substrate of the module. Pop the plastic cover off and put it under a microscope and using a strong light look to see if there are some really teeny cracks that propagate through the microstrip traces. This is a very common failure mode. If there are one or two they are usually in the chokes that feed power to the RF transistors. If you have a steady hand and a good microscope, you can repair these by bridging the broken trace with small gauge wire and soldering with a fine tip iron. I find that wirewrap wire or equivalent is pretty good for this.

I have an IC-3220H that had this problem. I was able to repair it by flowing just a tad bit extra solder onto the connection as the cracks were right next to the solder pad. So far it 's still working, if it happens again I might have to try your trick of bypassing the trace with a bridge. And yes, from what I've heard it's is a very common problem with this RF power module.

K4EEZ
04-03-2009, 10:12 PM
i also have had 2 of these radios, the first one the pin diode went, that was a quick fix once i took the cover off and located the RF pa and found the RF output pin by using a probe test leads and swr /watt meter
RF would go to one end of the diode, i remove my test probe to the other side of the diode and nothing..., took diode out and replaced it
rig works fine... ;)

2nd 2100h, belongs to my wife and the LCD was cracked, and no output, i replaced the LCD screen, it receives fine just no RF output what so ever, i grabbed my test probes once again, but there is nothing on the pa final, and there appears to be no pre drive eaether, so i am thinking that one of the pre drive transistors /circuits have gone south :(

I replaced the 2100h with an icom 27a so my wife has a radio...

ad: KU4HP-1