eHam Forums => Station Building => Topic started by: NN5KS on May 24, 2003, 10:20:56 PM

Title: Computer monitors CRT or LCD?
Post by: NN5KS on May 24, 2003, 10:20:56 PM
  I am planning to make some changes to my station, one of which will be adding a computer for rig control and working some of the digital modes.  I know from past experience that a CRT monitor (specifically Sonys) are absolutely wonderful signal generators across the spectrum.

  What I am wondering is: are LCD displays quieter or do they spew RFI as well as or better than CRT-type displays?  With the prices of 15" LCD displays dropping into my price range, I have been considering one for the station.

  I am sure several folks have used both and should certainly have some input on this question.

73 and tnx

Title: Computer monitors CRT or LCD?
Post by: G7HEU on May 27, 2003, 04:46:57 AM
Hello Kerry

I use a 'no name ' 15" TFT here. If you look at my profile you can see how close it is to my radios. Not shown in that photo is a FT-690 for 6Mtrs and a 2Mtr hand held.

I have tested all my radios with the monitor both off and on and I can't detect any interferance.

I hope that helps but don't blame me if you go the TFT route and have a problem!

Best wishes


Title: Computer monitors CRT or LCD?
Post by: N6AJR on May 30, 2003, 08:07:18 PM
look on ebay for a cheep laptop like a ibm 760. the 760 has a metal case, a compatible sound card, will run w95 or w98, andy you can get one working with a good battery for around $250.  ( these have a 3 gig hd, 14 inch screen , soundcard, a cdrom and you can get extra battries, a floppy drive etc for them, they are usually 133 or 166 pentiums)

The all metal case holds down the noise and I find them quieter than my crt screen.  I have a laserjet 4L and it makes more noise when it boots up than the rest of the stuff combined.

 Here is a trick too.  Get your self a 12 volt to 110 volt power inverter ($30 to 40 bucks for a 500 watt one) and plug this into your cigg lighter for running the laptop in the car mobile, or any of your small 110 items you use mobile.  My friend uses rechargeable electric drill in his work and plugs them into the 110 converter while driving between jobs, also can do the cell phone etc. one 110 converter is cheaper than 7 different 12 vold power plugs for your accessories.

hope this helps  tom N6AJR

Title: Computer monitors CRT or LCD?
Post by: WD8DKB on June 01, 2003, 05:39:02 PM
Hello Kerry.  I purchased an LCD monitor at Dayton this year due to r.f. interferance from my crt monitor. My antenna is very close to my shack because my shack is located in the attic and my dipole is mounted on the roof. This puts one leg of the dipole about 10ft. or less from the shack. As a result I could pick up the monitor RFI only too well. The LCD monitor still gives some RFI but not near as much as the CRT unit. For me it was worth the change. It also provided much more desk space and can be held by a much lighter weight shelf as well. Hope this info helps. Have fun. Max

Title: Computer monitors CRT or LCD?
Post by: WW1Z on July 16, 2003, 02:21:31 PM
I've heard that typically the LCD monitors are much quieter than the crt types. The LCD's hi voltage is a small inverter board for the flourescent light tubes. Not much noise there and, at least the ones I've taken apart are surprisingly well shielded. One warning, if it dies its back to the manufacturer or the dump. getting parts is next to impossible. Even when you are an authorized service place for said manufacturer! Some of the CRT monitors are well shielded but most are not, cost issue, just enough to get by. I've wondered if the FCC actually tracks modifications. One model, imported by a large US PC outfit, lost a lot of internal grounds and shields over the course of its production. The only real advice is probably the LCD will be quieter, but if someone you know has done well with a CRT go ahead. As a note I have a 15 inch Sony (CPD 110GS?) and haven't noted many problems. But I'm not much a HFer. My laptop I've been using for satellite trackig would be a serious problem if I was listening for a 2m down link, good luck. John

Title: Computer monitors CRT or LCD?
Post by: G7HEU on July 16, 2003, 02:32:38 PM

A couple of additions to my earlier posting:

I have discovered that my LCD monitor does cause a noise problem on one band - 40Mtrs. It took a while to discover because some displayed colours have a greater effect than others. Ironically the home page is one of the worst!

One of the other guys mentioned the changing spec on LCD units. There are only a handful of TFT panel manufacturers in the world and some big name companies use panels from other brands. That whole market is subject to supply and demand and 'allocation' of panels. It's quite common for a manufacturer to change TFTs without ammending the model number etc.

Best wishes



Title: Computer monitors CRT or LCD?
Post by: NN5KS on July 16, 2003, 06:55:58 PM
Thanks so much for the postings and the emails.  I have been given plenty of food for thought.  I am continuing to research the issue and, if I come up with something astounding I will certainly post it here.

Best regards,