AB7CQ & N7RPT

email: ab7cq@ebidpal.com

Tombstone, AZ 85638

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Yaesu DR-2X Repeaters & Henry Radio AMP Powered

2. LoadStar SG-4160B Signal Generator

Highly Recommended For The Hobbyist And Radio Restoration.

I writing this review for any hobbyist that may be looking for a great reasonably priced signal generator to fit the the beginners pocketbook, as well as those that restore vintage radios that need to be aligned. I own a LoadStar SG-4160B signal generator, I was extremly surprised that the device was extremely frequency stable, you do need a bit of a delicate touch when setting the last digit or two, but you'll get used to it and develop a feel for adjusting the frequency, just a little patience and you'll develop the skill. The price for these signal generators ranges between $150.00 - $180.

Recommended Modification

I made a digital readout modification to my SG4160B signal generator, I added an inexpensive frequency counter to the SG4160B generator, the modification is simple and quick, all that's required is a 200V or higher .01uF decoupling capacitor, a BNC connector, and a small length of miniature shielded coax, about .50 cents or less in total, drilling one hole in the back of the cabinet, a little patience and about 1/2 - 1 hour in time.

If you look around eBay you can generally find used inexpensive frequency counters, or at an amateur radio hamfest. I purchased a used DMI DigiMax D-500 frequency counter and interfaced it with the my SG-4160B, it made a perfect addition to my SG-4160B for aligning vintage radios and amateur radio gear.

I'm including a link to a great YouTube video that specifically addresss not only how to use the SG-4160B for vintage radio restoration alignment, it also shows in detail how to make the digital readout modification to the SG-4160B. It provides two options with regard to the modifying the SG-4160B, I chose the simplest of the two, which one you choose depends on which frequency counter modification you opt to interface with the SG-4160B.

https://www.youtube.com/watch?v=3Mgg8wvyDHw

3. MFJ 259, AW07A,& Other Antenna Analyzers

This article has to do with MFJ, the AW07A, and other antenna analyzers exhibiting frequency drift, it does not apply to newer graphical antenna analyzers.

These older generation antenna analyzers are subject to a fair amount of frequency drift when powered with internal double (AA) batteries. In a word, they eat batteries like my dog eats puppy treats.

As the batteries degrade these analyzers cause increased  frequency drifting. When the voltage of the internal batteries of the MFJ-259 series, or the AW07A drop below 12 volts, stability becomes more noticeable, and at 10 volts, forget it, frequency drift is like watching a drunken sailor walking down a peer.

I’m not suggesting that these antenna analyzers are junk, or useless instruments, what I’m suggesting is that you need to use an alternate power source which can keep the voltage constant at 12V DC. This can be accomplished with batteries with sufficient current handling capacity keeping the voltage constant for an extended period of time, a regulated 12V DC (12VDC - 12.5VDC) power adapter that plugs into an 115V - 120V AC outlet, or a 12V power supply cord that plugs into your vehicles cigarette lighter. The car battery in your vehicle will keep the voltage constant. Personally, I wouldn’t trust the results of what the antenna analyzer is telling you if you power the device with eight (8) 1.5V batteries. Above all, MAKE SURE THE POWER SOURCE IS REGULATED AND FUSED.

The antenna analyzer will still exhibit some drift, they all do, however, it will perform exceedingly better from these alternate power supply sources and be more accurate.

If the antenna is located at a remote site, like a repeater site, generally a 110 - 120 volt source will be available, or a back up battery(s) for the repeater(s), if neither of these sources are available, then you’ll have to transport a gel cell, tractor, or motorcycle battery along with the other instruments and tools to the site to work on the antenna ........ there’s always a way.

There are high tech antenna analyzers which are much more stable, however, they can cost you $600 to over $1,000 that cover the HF/VHF/UHF, all the way up to 2000MHz.

4. Spectrum/Network Analyzers

Right from the start the average ham can't afford the cost to purhase spectrum/networks analyzers. Even a few years ago these instruments were out of reach for most hobbyists and hams, not so many years ago I remember back in the 70's and early 80's one could expect to layout up to $35,000 for one, however the cost has decreased significantly due to advances in technology making them much more afforable. Actually, prices have reached astronomical lows.

So what is "afforable?" Truth be told, some well repected instrument manufacturers now offer quality entry level spectrum analyzers for around $1,000, not $75 - $100 toys on advertised on eBay, which are well suited for the hobbyist and amateur radio enthusiast. YES, $1,000 is still a sizable piece of change, but considerably less than what it used to be. Chances are those transceivers you chat on most every day cost near as much for a single all band rig. 

Companies like Rigol offer decent reasonably priced analyzers well equipped, one of the most popular is the Rigol DSA815-TG, the TG means that it includes a tracking generator, typical cost is around $1200. Why is a tracking generator important, well for one thing if your into repeaters and want to tune up a duplexer for a repeater, you'll need a spectum analyzer with a tracking generator. I won't elaborate on all the things you can accomplish with a spectrum analyzer, you can visit a manufacturer's website to review the specifications of various models and prices.

I have to be honest, I'm biased and believe that the Rigol instruments are a step above most, in my opinion the Rigol DSA815-TG bechtop analyzer is the best of affordable analyzers for the hobbyist and skilled amateur radio operator, it's an outstanding analyzer with lots of bang for the buck, featured packed and includes a 3 year warranty. My test bench is comprised of numerous test instruments and all bare the Rigol brand name. YES, I'm prediduced, but I base that consenus on my personal experience. Everyone has to make their own choice and do their own research before purchasing. 

It's important to understand that if you haven't a lot of electronics experience you're going to experience a large learning curve before you know how to use sophisticated bench instruments, perhaps a technical colleage may be a good place to start to learn electronics, if you're good at self learning you can learn on your own and at your own pace, or perhaps a friend you know whose highly skilled in electronics get started in the right direction.

The bottom line, if you have interest in working on and repairing electronics a spectrum analyzer is a great tool for your radio shack test bench.

5. Juntek Programmable Signal Generator.

The Juntek PSG9080 Signal Generator is decent reasonably priced signal/arbitrary signal/waveform generator, selling for an average of $198.00 to $230.00. For those on a limited budget, this is an excellent choice.

The PSG9080 in my opinion is the best of the bunch in the lower priced signal generators, unless you choose to step of to a Rigol, Rohde Schwarz, Keysight, Tektronics, and  etc., they're considerably more expensive costing 3 to 4 times as much. Truth be told, you can get a lot of bang for the buck for a lot less money if you choose a Juntek PSG9080, and it's featured packed, and a great signal generator. Especially for the ham who needs an test instrument for the budget minded ham's test bench.

The down side is that generally you'll have to order it on line on places like eBay and Amazon, they're shiiped out of China, and shipping can take approximately 2 -3 weeks for delivery. I think it's worth the wait and savings.

The second thing you need to do is make a 10 - 30 minute modification. Most electronic test instruments produced and coming out of China are not earth gounded, they are equipped with a USA style 3-wire electrical plug, but it's not really properly earth grounded. There's information on YouTube that will explain how to perform the simple modification, or you can contact me and I help you with how to perform the mod.

Outside of this, the Juntek is an excellent signal generator, and YES, it will produce sufficient modulation/signal for aligning radios up to 80 MHz (HF). It's capable of both internal and external signal source, it will produce AM, FM, PM, ASK, FSK, & PSK modulation. It has a great easy to read color display, great keyboard, dual; channel, RS232 interface, and many more features. Don't let RS232 scare you, there are RS232 to USB cables available on eBay, Amazon, and you might even find one at Walmart. It also comes with software for your Windows PC.

The unit is well constructed with quality PCB boards and components, I was surprised after examining the quality and it's light weight. YUP, comes with a decent user manual.

I would like to see Juntek come out with a version covering up to 1 MHz to 470 MHz, (HF, VHF, UHF).

6. MFJ-894 SWR/Wattmeter Calibration

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