AB7CQ & N7RPT

email: ab7cq@ebidpal.com

Tombstone, AZ 85638

Click Radio Image In Upper Left Corner To Return To Home Page

Yaesu DR-2X Repeaters & Henry Radio AMP Powered

Product News

MFJ Bia Tees, Any Model

If you purchased any auto coupler from MFJ that includes a MFJ-4117 Bias Tee or other model, be cautioned that you should inpect the Bias Tee thoroughly before applying power to the antenna coupler installation.

MFJ sells several antenna auto couplers, those are the antenna coupler types that are installed at the antenna, they include a Bias Tee that's used for providing power to and controlling auto coupler, unfortunately, these Bias Tees are the subject of horrible quality control.

Many of them have shorts to ground, defective switches, or even out of spec internal components. These defects can manifest themselves by causing fuses to blow, damaging your power supply, the antenna coupler, or worse, your transceiver, they're smoke producers. This stuff is a product of China.

Before you install any MFJ auto coupler that uses a Bias Tee, open it up and thoroughly inspect and test it so you're sure that it's in 100% working order. We've found shorted switches to ground and defective, or out of spec components used in the Bias Tees. This includes the 12V power supply connection (plug/socket), many of these are very low grade and are a loose/sloppy fit. They should have used a water tight coaxial type connector for supplying control wiring and 12V to the device like SGC couplers. Also be sure to use a sufficient wire size for the 12V DC power control line to the antenna coupler, insufficient wire size can result in considerable voltage drop to the coupler causing the antenna coupler to malfunction.

My advice, if you're considering an antenna auto coupler, purchase an SGC auto coupler, they're designed to meet military specifications, the cost is not that much more than a MFJ auto coupler ...... and they work flawlessly, and are made in America. I used them for 41 years, never experienced a defect or failure, my last installtion in service today has been in operation for 21 years at my current location, still working flawlessly.

Note: I'm not compensated by SCG for recomending SGC antenna auto couplers.

FTM-100DR Bug & Fix & Update 10/30/2018

OK, I chased this one around for better than a week, don't laugh, it's true.

I purchased two new FTM-100DR's & a FTM-400XDR in March 2018. All three worked just fine until early September 2018. Of the three radios, one started to exhibit a strange anomoly.

The radio would start just fine, BUT, the DX mode change would't work, the radio wouldn't transmit, and there was no receive. If I waited approximately 4 - 5 minutes, everything would start functioning properly ..... keep in mind this issue was with only one of the three radios.

I checked power supply voltage, vehicle voltage wiring/monitoring, reset the radio to the factory default, reformatted the SD card, tried a new SD card, reloaded the data back onto the SD card, reset the control head to the factory default, exhanged the control head with another, changed seperation cables, reloaded the MAIN, PANEL, & DSP firmware, ran voltage checks/monitoring, every possible avenue was explored, but still the FTM-100 would not behave properly. I began to suspect the DSP unit.

Update 10/30/2018

Well, I had to ship the transceiver back to Yaesu for service/repair. Given that we're dealing with SMD technology and that the radio is under warranty I choose to let Yaesu work out the problem. I'm quite capable of working with surface mount technology and own the equipment to do so, but what's the point, the transceiver was under warranty and Yaesu has the replacement components and boards, so why should I undertake a repair. These types of issues can be pretty elusive, I chatted with the service tech's at Yaesu and they agreed that it was probably the DSP unit and appeared to be temperature senitive.

Update 11/15/2018 - The Repair/Fix

I received the repaired radio back from Yaesu.

As it turns out, the DSP Unit which plugs into a connector on the top of the board was in fact defective and had to be replaced. If you experience these same problems with your rig it's a good chance that either the DSP Unit is defective, or it's not firmly seated in the socket. One thing I noticed was that the DSP Unit which is approximately 1" to 1-1/4" square is not really supported as well as it should be, there's a chance that it could come loose and not be seated properly. This could also happen when installing upgrades like the FVS-2 Voice Unit, or the Bluetooth Unit, the DSP Unit could come loose, double check everything before closing up the radio.

When the top cover of the FTM-100DR is secured to the transceiver the DSP Unit is making contact with the underside of the top cover, I suspect this is required to help dissipate heat away from the DSP Unit ........ if so that's a poor way to do it, just a guess.

You are here: Home-Product News

Previous Topic: Local News Next Topic: WIRES-X Usage