Manager - NA4M
Manager Notes

Reviews For: Comet CMX1

Category: SWR & Wattmeters & Dummy Loads

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : Comet CMX1
Reviews: 2MSRP: 210?
Cross Needle Remote Sensing SWR Meter
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
K7DAA Rating: 2010-09-10
Not bad, but cable too short for use in mobile Time Owned: 0 to 3 months.
First of all, here is the URL for the CMX-1 meter:

...or just go to and then navigate through the menus.

I bought this at HRO for $169.95 last week, intending to use it in my HF mobile setup. I have a Yaesu FT-857D, Ameritron ALS-500M linear, and Little Tarheel HP screwdriver antenna. Running 500 watts means that you really want to make sure you have tuned your antenna properly to get a decently low SWR, so I decided to try this Comet cross-needle design.


-- Switchable backlight via a small slide switch on the right side of the display head.

-- Nice, non-glare backlight and meter coloring. This is the main concern I had, since I want to have the display mounted towards the top of the dash area so I can still keep my eyes on the road. This puts it ahead of the very bright, non-dimming display on the Ameritron AWM-35.

-- DC power input is on the remote sensor, which you would typicall have in the rear trunk area in an HF mobile installation.

-- With the backlight off, current consumption is nil, so you can leave it powered from the car battery full time.

-- The lowest of the 4 front-panel buttons is a spring-loaded button that you can press in any time to check your battery voltage. You can do this without deselecting whatever power setting you had for SWR, so that's convenient. The Ameritron meter does not have this function.


-- IT ONLY HAS A 6-FOOT CORD BETWEEN THE DISPLAY HEAD AND THE REMOTE SENSOR!! That is a non-starter for mobile use. Comet sells a 10-foot extension for this, but add another $25 or so. At least it's available--I'll give them that. HRO had several in their system, but none at the store I was visiting. More about this below.

-- No capability to display peak envelope power. This puts it at a disadvantage compared to the Ameritron AWM-35 remote-reading meters. I plan to void my warranty and add a small switch and circuitry for PEP. I also did this for my Bird Thru-line meter.

-- Calibration doesn't appear to be its strong suit. Measured 450 watts average power on the top scale, then switched down to the 300 watt setting, and got about 275 watts indicated. I will re-calibrate this to my liking, but Comet doesn't make any claims for accuracy or repeatability in their literature. Maybe this is why.

-- "Owner's Manual" is a bi-fold sheet of paper with hook-up instructions and not much else.

--The pointers on the cross-needle display are quite thin, and are a bit hard to read at night when taking a quick glance at the meter. If you look at it a bit off-angle (if it's mounted to the side a bit) this is less of an issue.

-- The battery voltage scale on the face of the meter is only a small portion of the display, showing something like 10 to 16 volts. Again, not the most accurate (is it 12.5 or 12.7 volts? You'll never know...), but it's a nice feature. I use the built-in digital battery voltage display on my FT-857, which is much more accurate and useful, and it is there full-time.

While I am reviewing this meter from the standpoint of an HF mobile operator, it is perfectly suitable for a fixed station as well. If you are using it in your home station, the 6-foot cord might be plenty long for you. I'm just pointing out that it's not nearly enough for a trunk-mounted system, which is often what you will do if you run QRO mobile.

The interconnection between the display unit and the remote sensor/power input unit is via a pair of inline 4 pin DIN male/female connectors. One is on about 8 inches of cable that comes from the remote sensor, and the other 5-plus feet of cable is permanently attached to the head unit. In order for me to use this in my mobile, I violated my warranty and desoldered the DIN connector from one of them to add another 8 feet of shielded 4-conductor cable. Not major surgery, and it works fine that way for me.

So, all-in-all, not a bad mobile accessory, but definitely not a lab-grade meter. It's within $10 of the Ameritron meter, is a more eye-pleasing grey color body with a colorful display. If you've seen the remote meter/control for the Ameritron ALS-500M, you've seen the Ameritron ALS-35 or 35M, although the 500M head is a bit smaller and thinner.

I thought about both of these brands, and possibly would have bought the Ameritron if HRO had both brands in stock. My store did not. The Comet definitely looks more at home in a modern car interior, no doubt about that. I'm more interested in function than style, so I probably would have bought the Ameritron because of its ability to switch the display between PEP or average power--something useful to have if you operate SSB or CW.

If I were to grade this accessory based solely on mobile operation, I would have given it a 3 due mostly to the too-short cable. Overall, though, I think a 4 is more fair, given that it will work just fine in a home station as well.

Feel free to email me at my email listed on if you have questions or want to discuss further!


Dave - K7DAA
KB0USY Rating: 2005-03-20
What not PEP Time Owned: N.A.
Looked this meter over at the Claremore,Ok hamfest.When I first seen this I reached into my pocket for the money.Then while reading the specs I seen it has no PEP.It's agreat looking meter for mobile.It lights up sweet.If it had the peak reading it would be in my mobile.Thanks