Unfortunately, I made my decision to go with the MFJ-113 before seeing K5LXP's post on the travel clock. In hindsight, I think that would have been a better choice.
When I first opened the plastic packaging the MFJ came in, I heard something rattling around inside the clock. I didn't want to plug it in, thinking the loose part could be a screw, which would short out.
I shook the clock several times until a small piece of red plastic - probably broken off from the inside of the bezel - dropped out. There was no obvious damage to the bezel, except a slight scuff which does not interfere with the display.
Plugging the clock in, I was impressed with the size and brightness of the display. I would certainly not have any trouble reading it from anywhere.
However, the look and feel of this clock is cheap. I guess this is what we have come to expect from MFJ these days. But it's only a clock; not a radio or anything critical like an antenna switch. That's why I chose the Alpha Delta antenna switch, and not one from MFJ.
The clock appeared to function properly. I set it to the 24 hour format.
But later in the evening, I found that the leftmost digit of the display had only one segment lit. The time was 20:23.
Here is what it looked like:
https://drive.google.com/file/d/1TkqJOLkXD4V3izSKY0f6N7LbDdp41b19/view?usp=sharingIf I tapped the case, I could get the digit to light properly or not.
At this point, I had two choices:
1. Contact either Gigaparts where I had purchased the clock, or MFJ - depending on the return policy - and ship it back for a replacement or a refund.
2. Open the case and check it out for myself.
Considering that I would have had to pay return shipping, then wait who knows how long to receive another (probably defective) unit, I decided to do what we hams do, and attempt repair myself.
I figured the problem was just a poor solder joint, which I could fix easily. If it turned out to be something else and non-repairable, I could just pack it up and send it back.
Opening the case, I found yet another example of MFJ poor quality and workmanship. The PCB's are all phenolic (well, what did I expect, G10/FR4 fiberglass? NOT).
Then there is the main PCB just hanging from the display PCB on its stiff flat cable. This isn't really an issue though, as the cable is substantial, and this clock isn't being used in a vehicle or other high-vibration environment.
I could not detect any poor solder joints, so I plugged the clock in and carefully inspected it. I quickly found the source of the problem: The 12/24 hour switch. It is one of those $0.01 switches with a set of contacts on the bottom, just sitting on the PCB, held in place only by the plastic housing of the case.
There was grease on the switch contacts and PCB, I assume to allow the switch to move freely. I am familiar with this type of grease being used in larger switches handling some current, but I would think that it would only impede the flow of current in this extremely low current circuit. The grease was on the 12/24 hr and the alarm switches.
I removed the grease with rubbing alcohol and replaced the switch body. Still the contact was not good. So I began playing with the contacts, bending them outward to apply more pressure against the PCB.
This appeared to work, and I re-assembled the clock.
It is now working properly.
I have decided that when (not if) the switch loses contact again, I will jumper it out in the 24 hour position. I will also jumper the alarm switch to off, since I will never be using that feature.
When I do need to open the clock again, I would like also to investigate adding a brightness control - using a photo detector of some sort. I don't know if the clock chip they used has this feature, but I suppose I could design a simple circuit regardless.
The display is very bright. Not really a problem for me, but it would have been desirable to have the display dim when the room is dark.
I thought that MFJ could build something simple like a clock, but I guess not. The design and QC of this product is the poorest I have ever seen in such a product. Even the old Radio Shack clock which this one replaced was better made. It was still working after 20+ years. I only wanted to replace it with a 24 hour model with brighter display. Well, at least the MFJ does fit that bill. But I am absolutely certain that 20 years from now, this clock will be at the bottom of some junk heap (or its parts will have been recycled).
I can say without doubt that this clock is the last MFJ product I will ever buy.