| Author |
Message |
    
Texasyankee
New member
Username: Texasyankee
Post Number: 7
Registered: 1-2006
| | Posted on Friday, January 13, 2006 - 1:15 am: | 
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i'm kind of confused on what filter i should install
i have a ic-718 and have a choice of 3 different filters to choose from
all 3 would be nice to have but the 718 has space for just 1 optional filter
i can use a 1.9,2.8 or 3.3khz just not sure which one
let's face it these filters aren't cheap and i don't want to just spend money on the wrong one
thanks everyone
chris |
Bruce
Senior Member
Username: Bruce
Post Number: 3403
Registered: 9-2003
| | Posted on Friday, January 13, 2006 - 10:49 pm: |
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2.8 is standard |
Rldrake
Junior Member
Username: Rldrake
Post Number: 15
Registered: 1-2006
| | Posted on Saturday, January 14, 2006 - 7:44 am: |
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There are many more than just 3 filters available for the icom 718. Before you go soldering an additional filter in it, you need to figure out why you think that you even need one. What is it that you want to accomplish? International Radio's (Inrad) website might be a good place to get a little insight on optional IF filtering, as would some reading in some of the basic text books on amateur radio (ARRL Handbook, etc.). 73 |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1007
Registered: 6-2004
| | Posted on Saturday, January 14, 2006 - 11:08 am: |
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There are good and bad things about each bandwidth. 3.3kHz is wide and gives the best SSB audio, but it's not very selective when the band is busy. 2.8kHz is pretty much the standard bandwidth as Bruce said, and it'll offer a bit more selectivity than the 3.3Khz, but won't sound quite as good. 1.9kHz is very selective and would be best used for very congested band work - such as during a contest - because it'll really cut down the audio fidelity.
Does your 718 have DSP? If it does, then a really good way to hear the difference between filter bandwidth is to use the DSP at those bandwidths. Otherwise, you might ask to listen to a friend's rig with a particular bandwith filter to see what it does and doesn't do well.
Generally I don't use a SSB filter if I don't need it because the audio is better. I run wider filters until it's necessary to use a SSB filter, and then I use the filter that I think will work best while still allowing the best audio. I have three to choose from in my radio. 2.4kHz and 1.8kHz at the 8.83MHz IF, and 2.4kHz at the 455kHz IF. I can use them separately or in combination as necessary, but I usually don't use the 1.8kHz filter unless it's absolutely necessary. |
Texasyankee
Junior Member
Username: Texasyankee
Post Number: 10
Registered: 1-2006
| | Posted on Sunday, January 15, 2006 - 10:11 am: |
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yes i have dsp in it.
there is no way to adjust the dsp though.
i also have an auto notch but again no adjustment |
Rldrake
Junior Member
Username: Rldrake
Post Number: 16
Registered: 1-2006
| | Posted on Monday, January 16, 2006 - 2:15 am: |
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The optional DSP (icom UT-106 board) IS adjustable via it's menu. You need to read your 718's operator's manual. |
Slugo4449
Member
Username: Slugo4449
Post Number: 63
Registered: 7-2004
| | Posted on Monday, January 30, 2006 - 3:36 pm: |
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The problem with the IC-718 is that you can only solder one filter in. There is an after market piggy backed set of filters that take up the one slot that the IC-718 has.
Try the W4RT website and look for the piggy backed filters one for CW and the other for SSB.
I think that I paid $180.00 for the CW filter only at a ham radio store. I think the dual filter is over $200.00.
The adjustment for the DSP is easy. Just hold in the button for "NR" and it shows on the readout. You adjust it with the VFO knob, then hit the "NR" button again and your back to operate.
Marty
KG6QKJ |
Rldrake
Junior Member
Username: Rldrake
Post Number: 41
Registered: 1-2006
| | Posted on Thursday, February 02, 2006 - 1:41 am: |
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I soldered the Inrad 450hz CW filter into my 718. I think it was $104. Very happy with it. |
