| Author |
Message |
    
Audiophile73
Member
Username: Audiophile73
Post Number: 66
Registered: 5-2004
| | Posted on Monday, March 07, 2005 - 12:34 am: | 
|
hey does anybody know what a good meter is. I need something that is better than the standard dosy meter. I need something accurate that can read both rms and peak watt reading. I am setting up a one driveng 4 setup. I need to get all my deadkeys right. Any input, would be great |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 116
Registered: 2-2005
| | Posted on Monday, March 07, 2005 - 9:16 am: |
|
If money doesn't matter, Bird is the standard and Coaxial Dynamics is a close second. There are various military surplus meters that are very accurate as well, but I'm not familiar enough to suggest a particular model.
If money is an issue, I'd suggest forgetting about peak reading and just get a decent average reading meter. I personally don't care about accuracy, so all I've ever owned is an average reading meter from that national electronics chain, and it works fine for relative output indications. I actually gave it to a friend who has a Bird 43, and it's pretty close in accuracy too.
Peak reading meters aren't a terribly accurate way to measure PEP output. Some meters just use a capacitor to allow peak reading, but the most accurate peak reading meters are powered by a battery or some other source to do it's job properly. Peak measurements should only be taken with a constant tone for accuracy. Using voice for peak measurements will never work because voice has a very wide dynamic range and changes in power output very quickly. It's so quick that the meter movement can't respond at that speed and swings around with the momentum of the meter movement itself.
You can use an average reading meter to guestimate how much forward modulation a radio has. By definition, an AM signal that is 100% modulated will show 50% more average power than the carrier alone. To get an accurate reading when you measure the carrier you should use a set of clip leads to key the radio so there is 0 output from the microphone, and you should use a constant tone for modulation measurements.
For those of you who use Texas Star amplifiers and wonder why they recommend a dead key of about 7 and a swing to about 9 - that's why. It's an average reading meter movement that shows relative output rather than a calibrated output.
Oscilloscopes are the only way to get very accurate PEP measurements. The scale has to be calibrated for accuracy and again, constant tones are used for measurements. |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 547
Registered: 7-2004
| | Posted on Monday, March 07, 2005 - 10:40 am: |
|
audiophile, you should look for 1 with forward & reflected power readings, swr if you don't want to look at crossed needles(however, if your reflected skyrockets, you know your swr's went POOF!)and scales that let you accurately set wattages. the astatics are decent w/F & R on 'em, but i know the OLD pdc's that they replaced measured PEP the capacitor way as X stated. (they measured pep with the lite off & power disconnected. can't say for sure about the new astatic ones)what you really need are scales set up to measure what YOU are setting. you need accuracy LOW power for the radio's dead key, 100w low on the astaic's MAY be close enough. & the 1000 watt scale is perfect for MOST 1x4's, definitely dead key & avg swing. heavily driven custom amps may swing past the 1kw limit, then you can look on the 5k, but it won't be as accurate. the $90 or so price range is the bottom of the decent stuff. i used a diamond sx100 til it died a couple weeks back & it matched right up with a bird 43 & did everything needed. around $150. i just got a palstar wm150m with a remote head so i can have the meter right in front of me in the mobile. doesn't measure swr per se, uses the crossed needle method, 300/3000 watt scales let me set amp dead key fine on 300 watt scale. & the 3kw is amazingly accurate-almost exact with the bird inline with a 1kw element. at $120 with shipping it was a good deal i feel, especially since i mounted the coupler right to the back of the amp with a barrel connector, that's 1 less long jumper cable to deal with & the meter itself is right on the dashboard when i need to watch it. other then autek, i don't know of any other remote types out there right now.abird with all the elements you'd need is probably going to end up close to $600 or $700 & the coaxial dynamics equivalant isn't much cheaper.
|
American_radio_18
New member
Username: American_radio_18
Post Number: 4
Registered: 2-2011
| | Posted on Wednesday, February 23, 2011 - 12:10 am: |
|
Hello, i just purchased a new TR-1000 mobile to run with my new 2970N2. My question is how accurate are these meters? Its saying i swing about 180 on AM and alittle less on SSB about 120 or so. I have a new 220amp alternator and ran high current 4ga cable from the alternator direct to the battery and high current 8ga to the unit. So i know im feeding the N2 the current it needs, about 50+ amps from what i understand. Shouldnt this unit be putting out 250+ pep on SSB and close to the same on AM? Or is the TR-1000 giving an average reading? |
Sitm
Intermediate Member
Username: Sitm
Post Number: 491
Registered: 1-2004
| | Posted on Monday, February 10, 2014 - 8:38 pm: |
|
I use a Diamond SX 240 C on one of my stations and am very happy with it. It isn't much of a "feel good" meter as it generally registers actually forward power and not harmonics. Here are the specifics.
The Diamond SX-240C is a precision SWR-power meter featuring cross needle design for measuring SWR and output power simultaneously.
This meter is rated from 1.8-54, and 140-470 MHz (Note: 220 MHz uses a correction factor).
Power ranges of 30W, 300W and 3KW (HF only). Reads: Forward RF power/Reflected RF power/ SWR, PEP monitor. Requires 13.8 VDC. DC cord included. The connector type on the rear panel is SO-239 (accepts a PL-259).
SX-240C Specifications:
* Scales: 1.8-54 [Sensor 1], 140-470 MHz [Sensor 2]
* Input Impedance: 50 ohm
* Power Ranges: 30/300/3000W HF only (74% of scale for 220 MHz)
* Power Readout: Direct readout. (74% for 220 MHz)
* Power Accuracy: 10% at full scale
* Mininum Required Power: 3W
* Input & Output Connectors: SO-239 [UHF]
* Size: 6.7 x 4.6 x 6 inches (170x115x150mm 1350g) |
Sitm
Intermediate Member
Username: Sitm
Post Number: 492
Registered: 1-2004
| | Posted on Monday, February 10, 2014 - 8:42 pm: |
|
On my other station I utilize a Daiwa CN-801 HP3 for HF applications and find it very accurate. Sometimes the light can be a tad bright, but it has three separate ranges and average and pep setting.
The Daiwa CN-801HP and the 801HP3 are cross-needle SWR/ Watt meters covering .8-200 MHz. The cross-needle movement allows the simultaneous monitoring of forward power, reflected power, and SWR, all without the need of an extra calibration procedure.
The meter is switch-able for 20 (30), 200(300), or 2000 (3000) watt full scale readings, and has a built-in lamp which can be powered from an external 13.8 VDC source. Supplied with a DC power cord, which is required for powering the built-in lamp and PEP measurements. |
Sitm
Intermediate Member
Username: Sitm
Post Number: 493
Registered: 1-2004
| | Posted on Monday, February 10, 2014 - 10:55 pm: |
|
My two meter application at the secondary station my 2 meter 440 meter is a Yesu YS-500. I really enjoy the meter with the exception that it isn't back lit. If you can get a hold of one in decent condition jump on it. |
|
