Batboard

Micor series TLE1713A-3. Looking for schematics, metering info, etc. and/or a manual if you have one to spare or can copy part of a manual. For non-commercial use in an amatuer repeater. The amplifier seems to be working fine. 2 Watts in ~90+ max Watts out (un-controlled) at 449 MHz. I will be controlling the output to use at the ~50-60 Watt level. I just need documentation at the rptr site for future reference. This way, if I have the documentation, I'll never need to fix it - Inverse Murphy's Law. Tnx.

George, WA2VNV

I have the schematic for the TLE1713A. Nothing about the -3 however.

I'll copy it and send it to you in the mail.

Bob M.

G,
I will give you a 100 Watt 3db attunator for it that I was using at the Mid Nassau site when we were running the 1/4 k amp .
I didn't think you needed it to reduce the output so I never thought you were going to run 50 watts
XD

George,

There's a Yellow wire on the RF Power Amplifier set at +4.5~5.0V DC that controls the RF Power Output on the TLE1713A UHF 440~470 MHz RF Amplifier. The RF Input Drive is /\/\ specified at 1.8 Watts for 75 Watts RF Output.

These /\/\ UHF RF Amplifiers are rated for Continuous Duty but I would highly recommend not to place your hands on the heatsink if the amplifier is being used in this configuration because they can get mighty hot. The ceramic hybrids are getting more difficult to find since /\/\ discontinued manufacturing them during the 1990s.

The /\/\ MICOR Product Line was discontinued in 1992 by the Marketing and Engineering Product Group. MICOR ran the course of ten (10) years for Parts Department support and component availability.

Regarding the -3 dB reduction in RF Power Output down to 40 Watts RF Output, I will recommend the use of the Power Control DC Voltage circuitry rather than a RF Attenuator. Using this method reduces the heat disappation, the RF Output and the DC Current draw in Amperes from the +13.8V DC Power supply.

If you are not using a standard /\/\ MICOR Unified Chassis in conjunction with this TLE 1713A RF Amplifier, then I would suggest purchasing an external 100 RF Watt Isolator / Circulator (Typical .5 dB RF Insertion Loss) from an OEM supplier on your TX Frequency and place it on the output of the UHF RF Amplifier to prevent RF mixing / spurious signals in the amplifier stage and then retransmitted over-the-airwaves causing Inter Modulation Distortion or InterMod to other users on the UHF Band. This is not a good problem to troubleshoot or have.

Dan

Thanks to all for the responses. I realized that I should be getting inexcess of 110-120 watts max output. Checked the finals and found one suspect. After major surgery changing out the final(s) substrate assy with another from a T74 mobile using four M9740 transistors, I can get in excess of 125 watts output. I didn't want to push it any harder. Now it's really Smokin!. It was easier/wiser to change out the substrate assy than to try to change one M9995 final transistor as it's possible to damage those tiny chip caps that I don't have an easy replacement for. Also RFParts.com doesn't have a cross for the M9995 (date code 1985) transistor, which would mean changing a pair or all 4 with MRF644 or 646 if pkg fits. Also gets kinda expensive. It would also become another research project I don't want to do. Maybe the -3 rev in the model number is for those M9995 unknown transistors. Anyway, I have it burning in at 75 watts out thru a ~200 watt isolator (ins loss <0.4 dB) into a dummy load. Ran it for ~30 min and no problem. Heatsink gets toasty warm as expected. I will be running the output at ~75 watts into the duplexer and see how it behaves. I was being a little too conservative at the 50-60 watt level. So, Skip, tnx, but hold off on the attenuator for now. Again, thanks for all the suggestions and help.
George

kcbooboo wrote:I have the schematic for the TLE1713A. Nothing about the -3 however.

I'll copy it and send it to you in the mail.

Bob M.

Any chance I could get a copy of that drawing, please Bob?

I will scan the schematic and put it up someplace where you can retrieve it. I'm pretty sure I just copied the info and snail-mailed it to George back in March.

Bob M.

Done. PM sent to VK4DOS.

Bob M.

My two bits worth:
See those little chip caps in the output coupling?
Run 120W if you wish, you will eventually see a burnt spot where the cap used to be.

The solder in this PA MUST be 2% silver bearing solder to help prevent leaching of the cap terminals.

The diagrams, as well as the repair procedures are in Micor Mobile, as well as base manuals.

I have some spare manuals, my customers have upgraded to MSF.
One last thing, if you overdrive the input you will fry the input transistor.