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Reviews For: Daiwa CN103 VHF/UHF Wattmeter

Category: SWR & Wattmeters & Dummy Loads

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Review Summary For : Daiwa CN103 VHF/UHF Wattmeter
Reviews: 8MSRP: 100
Cross-needle style of VSWR bridge for 140-525MHz
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
W4KVW Rating: 2013-04-17
A KEEPER FOR ME! {:>) Time Owned: 0 to 3 months.
Picked this meter up used for $50 & it looks & works great on both 2 meters & 440 mhz.The light is bright & lights up the display very well for EASY readability so I see no issues with it. {:>)
KC2PLJ Rating: 2011-03-20
Great Meter Time Owned: 0 to 3 months.
I ordered two of these meters, one with UHF connectors and the other with "N" type connectors for my UHF antennas. So far the meters work great and have no problems with accuracy next to my Bird 43.I won't get into specific numbers but lets just say that side by side little difference is noticed at higher power levels. They look nice sitting on the desk also with the back light on. Looking to buy a third for HF. KC2PLJ
AB0RE Rating: 2009-05-09
Daiwa CN103 vs Coaxial Dynamics Time Owned: 6 to 12 months.
I compared a Coaxial Dynamics wattmeter to my Daiwa CN-103M wattmeter. The Coaxial Dynamics meter is rated at +/- 5% accuracy of Full Scale, the Daiwa is rated at +/- 10% accuracy of Full Scale. The Daiwa has 20W and 200W power settings. I had VHF slugs for 10W and 100W for the Coaxial Dynamics, as well as UHF slugs for 10W and 50W. For the test I connected the Daiwa to the output of the Coaxial Dynamics meter with a PL259-PL259 adaptor.

Here are the results:

VHF 10W Slug in C.D. vs 20W setting on Daiwa:
- CD 1.5W, Daiwa 2.2W
- CD 4.8W, Daiwa 5.2W
- CD 10W, Daiwa 9.5W

UHF 10W Slug in C.D. vs 20W setting on Daiwa
- C.D. 1.00W, Daiwa 1.85W
- C.D. 5.2W, Daiwa 5.8W

VHF 100W Slug in C.D. vs 200W setting on Daiwa
- C.D 6W, Daiwa 5.5W
- C.D. 59W, Daiwa 63W

UHF 50W Slug in C.D. vs 200W setting on Daiwa
- CD 5.5W, Daiwa 5.5W
- C.D. 45W, Daiwa 39W

So, what'd we learn?

- The meters were not linear in their readings so calibration of one meter to the other, across different bands and at various power levels, would not be possible.

- Accuracy was "the worst" at very low power levels, showing as much as 85% differences between the two meters. However, given that the rated accuracy is based off the full scale power setting, this is to be expected when taking readings at 15 - 25% of the rated full scale power output. The Daiwa consistently read higher than the Coaxial Dynamics at the low end of the Daiwa's 20W power setting.

- At certain power levels, particularly those towards the middle-to-upper end of the "full scale" power setting, the readings were pretty close. (i.e. .5W difference at 10W between the two meters)

- It appears quite possible that both meters were within their rated accuracy ranges. (If you take 5% of the Coaxial Dynamics power slug wattage rating, plus 10% of the Daiwa's power range, the readings were always +/- the sum of these two numbers.)

Overall it was nice to see that for the most part the Daiwa is not too inaccurate and for amateur use, particularly towards the higher ends of the power settings, the Daiwa works great. If you have a 25W VHF or UHF radio you can typically get by using the 20W setting of the Daiwa, knowing your readings are going to be very close to those of the much more expensive Coaxial Dynamics meter.

Dan / ab0re

Earlier 5-star review posted by AB0RE on 2008-06-15

A buddy of mine bought the Daiwa CN-103L. I had him bring it by my place so I could check it out. Surprisingly, the readings were in line with a Coaxial Dynamics (Bird Equiv) unit that another friend had previously brought over to my house. The Diamond meters I've previously had (SX-400C and SX-40C) have all read high (i.e. 72W output vs 65W actual). The Daiwa appeared to be nearly spot on.

After testing out my buddy's Daiwa I purchased a CN-103M meter. The box says CN-103L, but I've noticed it has some other improvements over meters marketed as the CN-103L.

First, it has rubber guards that slip on the sides of the unit(not sure if this was simply packaging material of if Daiwa intended for people to leave this in place when using the meter). Second, the CN-103M has an LED backlight vs. an incandecent backlight of the CN-103L.

This meter is a clear winner over the Diamond meters, which I was also happy with, due to the Daiwa's very accurate power readings, easy cross-needle SWR measurement, and nice LED backlight.

My only gripe is the 20W or 200W power scale. The 200W scale is simply too high unless an amp is being used. **** I did find that you can transmit 25W into the meter on the 20W setting - the needle simply goes a little bit higher than the 20W mark. This allows you to take advantage of the meters accuracy as most meters are rated +/- X% of *full scale*, so if a meter was +/-10% of full scale it could, in theory, be off 20W on the 200W scale. ****

Simply put, you can't go wrong with the Daiwa CN-103M SWR/Power Meter.
KE5WYD Rating: 2009-02-07
Not bad for the price Time Owned: 0 to 3 months.
Good little meter. Picked it up just for a cheap way to check power out and SWR. Got the one with N type connectors on it rather than the UHF. Compared it to a General Dynamics R2670B Comm System Analyzer. Readings on the CN103 were about 12.5% higher on 70cm and about 23% higher on 2M than what was read on the R2670B.

Band CN103 R2670B
2M 6.0W 4.89W
70cm 5.5W 4.89W

The light is nice and bright when connected to a 13.8V source. The 20W and 200W range really should be changed to 5/50/500W or 10/100W. Over all its a good simple meter for checking power out and SWR.
G6YGZ Rating: 2008-11-14
Very Happy Time Owned: more than 12 months.
I have read alot of reviews where people are comparing the accuacy of the readings with far more expensive TEST equipment. I find the accuracy of my Daiwa meters reasonably good and rock steady. I use them for what I think they were designed for. This is to glance at whilst transmitting, to show the forward power needle is in the right area and the reflected power needle dosn`t move or if it does its very little. All the accurate testing and adjusting as already been done. The readings off the little Daiwas are just a check that nothing as changed and for less than £60 in my opinion there is nothing better.
KB9BPF Rating: 2006-07-16
Useful meter Time Owned: more than 12 months.
I've got two of these. One I keep in the antenna lead of my Comet multiband vertical (144/222/440 MHZ) for continuous antenna system monitoring and the other is for general purpose grab 'n' go use, like checking the antenna in the car for example. They've been treated carefully (I suspect they may not be awfully rugged) and have given consistent performance.

It's been a long time since I compared their readings to those on a service monitor, but my impression was that they weren't grossly out of cal. Since most ham measurements are relative-indication oriented, the Daiwa does OK. Since I use the CN-103 with FM rigs it doesn't matter that the passive peak-reading function is almost worthless due to its inability to accurately display peak power for SSB. (This is also true of the Daiwa CN-101L and MFJ-815B.)

Now, if Palstar would make a VHF/UHF coupler unit for its WM150M, that would make this Daiwa model irrelevant...
PE3HMP Rating: 2003-05-24
good value Time Owned: more than 12 months.
I own 2 daiwa CN103 meters (with N-connectors) work pretty good, even the power is within 10% accuracy.
Personaly I prefer the 103 with N-connectors
But I wished they made a 5,50,200 watt scale
VE3YES Rating: 2002-10-13
Okay for hobbiests Time Owned: more than 12 months.
I'm on my 2nd Daiwa meter as the first had a stuck pinion on one of the meters. The replacement works fine. Compared with Bird 43 (standard meter, with standard inaccuracies!) they both agree. The 20W and 200W power settings are poor choices for most mobile operators. They should've used 5W, 50W and 500W in my opinion! The SO-239 spigots work themselves loose over time. What can you say? Its a hobbiest-grade unit!