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#1
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Hello,
I recently purchased an Icom 756 Pro II for both ham and especially for use as a serious SWL DX radio. I am looking for other Pro II users who also do serious shortwave Dxing with this rig. My question is what settings do you find as most optimal on Filter 1,2 and 3 for DXing? Any other tips that improve SWL DXing on this rig would be greatly appreciated. 73 |
#2
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I've been DXing with mine about a year now and the settings I favour in SSB
mode a Fil1 - 2.9 khz with +300 offset Fil2 - 2.5 khz with +150 offset Fil 3 - 2.0 khz with - 100 offset That's for DXing AM signals in the SSB mode Of course in AM mode the filters are fixed at 3/6/9 khz, but you can swing the passband offset in the 3 khz setting quite a lot to good effect. In the lower tropical bands I would not use more than preamp 1 if any. The NR noise reduction should be used judiciously - toggle it on/off to see which gives the most audible signal. Conditions are great this morning @ 0600z 11,820 New Zealand is coming in nicely - haven't heard them in over a year NZ is always a very difficult catch here as the path lies direct over the Antarctic auroral belt. Also AFN Pearl Harbour nice and strong on 6,350 -- John Plimmer, Montagu, Western Cape Province, South Africa South 33 d 47 m 32 s, East 20 d 07 m 32 s RX Icom IC-756 PRO III with MW mods Drake SW8 & ERGO software Sony 7600D GE SRIII BW XCR 30, Braun T1000, Sangean 818 & 803A. GE circa 50's radiogram Antenna's RF Systems DX 1 Pro, Datong AD-270 Kiwa MW Loop http://www.dxing.info/about/dxers/plimmer.dx wrote in message oups.com... Hello, I recently purchased an Icom 756 Pro II for both ham and especially for use as a serious SWL DX radio. I am looking for other Pro II users who also do serious shortwave Dxing with this rig. My question is what settings do you find as most optimal on Filter 1,2 and 3 for DXing? Any other tips that improve SWL DXing on this rig would be greatly appreciated. 73 |
#3
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In AM I almost always use the 6.0 kHz setting. 9.0 kHz sounds great
but on the crowded SW bands its usually not an option. For SSB SWL DXing and amateur use I have the 3 positions set at 3.0, 2.4, and 2.0 kHz. One external piece of equipment that is great to have with this rig is an antenna tuner. The combination of matching the antenna to the frequency you are listening to and adjustment of the DSP NR to remove background noise really makes listening more enjoyable and also helps to pull out the weak DX stations. I can't wait to get a Pro III. They have to put them on sale eventually. Jim On 26 Sep 2005 18:53:38 -0700, wrote: Hello, I recently purchased an Icom 756 Pro II for both ham and especially for use as a serious SWL DX radio. I am looking for other Pro II users who also do serious shortwave Dxing with this rig. My question is what settings do you find as most optimal on Filter 1,2 and 3 for DXing? Any other tips that improve SWL DXing on this rig would be greatly appreciated. 73 |
#4
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Hi John,
Thanks for the quick and very informative response. I am going to try your settings to see if I get improvement over my settings. I had my Pro set as follows: Filter 1 2.2 with -125 offset Filter 2 2.5 with 0 offset Filter 3 3.5 with +125 offset I think that perhaps the 3.5 may be to wide and I am curious to see if the 2.9 will be more effective for my DXing. On AM the filter i seem to utilize the most for general listening is Filter 3/3.0 Of course, for very weak DX the SSB filters on AM are usually the most effective. Also, I noted you have the BCB mod on your rig. Do you know anyone in the states that does this mod. I am not very technically inclined. Anything else you find helpful on the Pro for BCB dxing? It is currently 0200 Z .. and Iran is coming in weakly on 9.495. This should prove useful for trying your filtering recommendations. Thanks again, David W5CTK |
#5
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Hello Jim,
Thanks for the comments, your filter settings are very similiar to the ones that John posted. You guys must be onto something! I will also at some point have to try adding an outboard tuner as you suggested. Like yourself, I would love to upgrade at some point to the Pro III as well. 73, David |
#6
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reply for David and Justin.
As it comes from the factory, the Icom 756 Pro series has the MW band, that is under 1600 Khz, attenuated. The mod that the local South African Icom agent did for me to restore full sensitivity below 1600 Khz on the MW band was based on diagrams supplied by friends in the States. I did not do the mod to enable the preamps below 1600 Khz, as I found the normal sensitivity more than adequate, a fact proved on my last three DXpeditions where the furthest and faintest of stations were logged (1 Kw at 8,000 miles away). Also, I use my Kiwa MW Loop and that can give a massive boost to very faint signals. The mods are not for the casual solderer, but best left to a professional with lab quality soldering equipment and desoldering gear, plus a lot of experience. If you want more info on these mods, please e-mail me privately and I will pass on your query to my friend in the States. If you are a serious MW BCB DXer, these mods are essential and work perfectly. -- John Plimmer, Montagu, Western Cape Province, South Africa South 33 d 47 m 32 s, East 20 d 07 m 32 s RX Icom IC-756 PRO III with MW mods Drake SW8 & ERGO software Sony 7600D GE SRIII BW XCR 30, Braun T1000, Sangean 818 & 803A. GE circa 50's radiogram Antenna's RF Systems DX 1 Pro, Datong AD-270 Kiwa MW Loop http://www.dxing.info/about/dxers/plimmer.dx wrote in message oups.com... Hi John, Thanks for the quick and very informative response. I am going to try your settings to see if I get improvement over my settings. I had my Pro set as follows: Filter 1 2.2 with -125 offset Filter 2 2.5 with 0 offset Filter 3 3.5 with +125 offset I think that perhaps the 3.5 may be to wide and I am curious to see if the 2.9 will be more effective for my DXing. On AM the filter i seem to utilize the most for general listening is Filter 3/3.0 Of course, for very weak DX the SSB filters on AM are usually the most effective. Also, I noted you have the BCB mod on your rig. Do you know anyone in the states that does this mod. I am not very technically inclined. Anything else you find helpful on the Pro for BCB dxing? It is currently 0200 Z .. and Iran is coming in weakly on 9.495. This should prove useful for trying your filtering recommendations. Thanks again, David W5CTK |
#7
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Icom 756.That's one of them little teentsy weentsy little bitty hand
held radios,isn't it? cuhulin |
#8
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Reference to the official Icom 756 Pro III spec sheet will show you that the
MW band below 1.8 Mhz is attenuated by 11 dB, a significant suppression that will prevent you hearing that really faint distant DX. The mod to remove this suppression is to be found on: Sheet 4 reverse side (back) of the "schematic diagram" at the top just left of the middle of the diagram. the mod is bridge R801 to R803 disable/disconnect C802 I am told that the schematics for the Pro/Pro II may not be the same as for the Pro III The mods for the 756 Pro have been described in great detail by Dallas Lankford and a Google search will reveal them. Look for: IC-746Pro Impressions & Mods Dallas Lankford, 6/13/04 -- John Plimmer, Montagu, Western Cape Province, South Africa South 33 d 47 m 32 s, East 20 d 07 m 32 s RX Icom IC-756 PRO III with MW mods Drake SW8 & ERGO software Sony 7600D GE SRIII BW XCR 30, Braun T1000, Sangean 818 & 803A. GE circa 50's radiogram Antenna's RF Systems DX 1 Pro, Datong AD-270 Kiwa MW Loop http://www.dxing.info/about/dxers/plimmer.dx "Bart Bailey" wrote in message ... In posted on Wed, 28 Sep 2005 16:21:30 +0200, John Plimmer wrote: Begin As it comes from the factory, the Icom 756 Pro series has the MW band, that is under 1600 Khz, attenuated. I think all bands outside of the one you're tuned to are attenuated, that's why the dual VFOs are best used on frequencies within the same range, but I haven't noticed the MW region to be any more attenuated than any other. I use either a tunable loop or a 42 foot vertical depending on target and conditions, and get good results. The mod that the local South African Icom agent did for me to restore full sensitivity below 1600 Khz on the MW band was based on diagrams supplied by friends in the States. I have the full set of schematics that came with it, but it's no trivial task to spot a band specific feature. Maybe you could post the chip involved and I could focus my search? I did not do the mod to enable the preamps below 1600 Khz, as I found the normal sensitivity more than adequate, That's the mod I was referring too, if such exists, besides, you don't have to enable them if you don't want to. I actually use the attenuator on local stations if I want to get a better view of their signal in the spectrum scope. side note - I enjoy trying to dig weaker distant stations out from underneath strong locals, for example Here in San Diego KFMB 760 is a monster, but just next door (at night) is a station on 770. It's programming isn't particularly interesting so I haven't listened long enough to confirm the call (I think it's KKOB Albuquerque, NM ). Another weak adjacent target is 810 KGO SF which is next to 800 XESPN Tijuana. I use upper sideband on KGO 810 and can actually employ the wide 3.6kc bandwidth filter to get reasonable quality audio. Back before XESPN 800 became an affiliate for the entertainment sports network, it was an over-modulated XEMM ("Musica Mariachi") that no amount of filtration could overcome. -- Bart |
#9
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In article ,
Bart Bailey wrote: side note - I enjoy trying to dig weaker distant stations out from underneath strong locals, for example Here in San Diego KFMB 760 is a monster, but just next door (at night) is a station on 770. It's programming isn't particularly interesting so I haven't listened long enough to confirm the call (I think it's KKOB Albuquerque, NM ). Could be KTTH Seattle, "The Truth". Rush Limbaugh & the like. Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) |
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