Watt/SWR Meter with Auto Antenna Tuner

[K1JWJ]

My first couple of years as an amateur, I have been using an older MFJ-949E manual antenna tuner. It works well and I like the cross needle readout for peace of mind.

Getting lazy in my old age and am considering the LDG IT-100 ATU for my new IC-7200 rig. But, no meter on that tuner.

I don’t know if I trust the LDG to “tune” without being able to see the resulting SWR before my eyes like I can now. And, SWR readouts on HF rigs are nortiously inaccurate.

So, should I add a meter between the ATU and the rig? If so, what meter offers the most bang for the buck?

Or, ought I just trust the tuner to do its job?

Grateful for all input.

73, Jeff

 

[wyShack]

I would just use the SWR meter in the rig if you want to verify what the tuner is doing. Any difference in SWR reading is unlikely to be even noticed on your signal. As long as the rig is not back down due to SWR I would call it good. If using a dipole or beam if the SWR is under 2:1, the tuner is likely causing more loss than the mismatch.

Any antenna that requires a transmatch is going to be a bit of a compromise anyway.

Above comment are for HF but for the most part will work up to 70 cm-matching at the antenna with a fixed matching system works best. On HF most of us use a matcher to cover all the bands.

73

 

[popnokick]

I use an LDG-IT-100 w/my Icom 7100. Assuming it works similarly in the IC-7200 you can switch the LDG tuner out of the coax path from controls on the radio and let the SWR meter on the radio give you a reading without the tuner.... which is usually what you're doing for comparison purposes anyway. I've had my IT-100 for more than a year now and it works quickly and precisely. I forget that it has memories for tuned positions, resulting in my pushing the Tune button on the 7100 again because the IT-100 didn't "kick in" and tune on the 1st press. Which defeats the whole memory advantage, because the 2nd press simply forces it to retune what has already been set.

 

[SCPD]

Personally I just let the auto tuners do their thing, and as mention'd, as long as they don't back down the output on the transceiver I figure everything is copacetic.
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I have used auto tuners (mostly Icom's made for the Marine services) for many, many years, both professionally and as a ham. In my early days with these tuners I'd try various SWR bridges at differing tap points; Without fail they really did their job as advertised. Only on a few isolated occasions (like trying to match a 15 foot vertical to a 1.7Mhz signal) did they balk at me and refuse to load. Today I am comfortable enuff with them I don't check anymore.
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Enjoy your new antenna tuning freedom Jeff !-- just don't ask the little tuner to do something you know in your heart- of- hearts should not work.......
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...............................CF

 

[AK9R]

If you really want some metering on the tuner, like you had with the MFJ 949E, choose the LDG AT-100ProII. With the optional control cable, it will interface perfectly with your IC-7200.

Products LDG Electronics

 

[N9PBD]

I personally have a power/VSWR meter between the tuner and the antenna, so I can see what the mismatch between the antenna and the tuner looks like. If you have your VSWR meter between the tuner an the rig, you'll mostly see a nearly 1:1 match (if your antenna isn't too far out). I just use my rig's SWR metering to see that.

 

[jwt873]

I use the LDG AT-100 mobile with my IC-7000 mobile setup. I trust the rigs SWR meter.

The tuner can match a 102 inch CB whip to work reasonably well from 20 through 10 meters. I also use it with my Hustler mast and resonators to extend the coverage slightly on the lower bands.

 

[majoco]

You don't need to buy another SWR meter..... from the MFJ tuner manual.....

To use the wattmeter without the tuning circuit select one of the
ANTENNA SELECTOR positions under BYPASS.

...so you can leave the MFJ tuner in the line between your transmitter and the new tuner. Better still, put the new auto-tuner out at the antenna where it will do the most good. Manual tuners are invariably right by the Tx, but this doesn't protect the coax if you have a high VSWR between the antenna and the tuner - so with the tuner at the antenna you have a low VSWR matched to the 50ohm coax cable which you will be able to see on your MFJ VSWR meter in the shack. The only problem is you will need to run some power out to the tuner.