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Sony ICF-SW7600GR 7.5" Loopstick Mod Completed
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Hello Guys,
Although it's a little too large to qualify as an Ultralight radio, the ICF-SW7600GR provides fairly competent MW performance in a compact, SSB-capable design. For those MW DXers unable to accommodate an ICF-2010 for space or financial reasons, this Sony portable would be perfect as an SSB "spotting receiver" for Ultralight radio transoceanic targets on an ocean beach... if only it had more sensitivity. Having had an unused unit sitting around since the Ultralight "Boom" started late last year (and faced with a situation where a multi-family vacation would make packing space extremely limited), there was a sudden compulsion to replace the stock 4.75" x .37" loopstick with a much more effective Amidon 7.5" x .5" loopstick wound with 40/44 Litz wire. This MW frequency-optimized combination has provided an incredible sensitivity increase in the SRF-39FP and Eton E100 Ultralight models (enabling both to receive Australia signals at Grayland), and I was curious how far it would boost the performance of this compact SSB portable. The ICF-SW7600GR has a stock loopstick very similar to that of the ICF-2010, in which a fixed larger center coil is mated with a much smaller tickler coil, used for adjustment of the unit's spurious signal rejection. As such, the instructions for "supercharging" the ICF-2010 (currently posted in dxer.ca's Ultralight File section) are electrically applicable to the ICF-SW7600GR, although the lsmaller unit has a large coil inductance of 983 mh, and the stock loopstick does not have a snap-out design like the 2010, requiring the hobbyist to use a moderate amount of effort in separating the glue at the base of the ferrite bar. The performance improvement for this $30 modification has certainly exceeded expectations! When the stock unit was checked against a stock ICF-2010 prior to modification, it was clearly inferior in sensitivity on all frequencies. The stock 2010 was far more effective in digging out weak daytime fringe stations, with or without the Synch function. After the ICF-SW7600GR received the Amidon 7.5" loopstick, the situation was completely reversed. The still-compact SW7600GR now clearly outperforms the stock 2010 on all MW frequencies-- low, middle and high band. High-band performance is particularly striking, with Synch lock performance on a 1610 TIS station completely inaudible on the stock 2010. This has been achieved despite a very modest expenditure for parts (about $20 for the Amidon ferrite bar, and under $10 for the Litz wire and other items). The modified SW7600GR is also much smaller and lighter than a stock 2010, providing a very practical, compact SSB "spotting receiver" for Ultralight TP/TA chasers. Two pictures of this modified ICF-SW7600GR have been uploaded to the "ultralightdx" Yahoo Group site, in the "Roll Your Own DXing Monster" album. It is hoped that various MW DXers will feel motivated to modify their own ICF-SW7600GR units, and obtain the outstanding MW performance possible with this model. 73, Gary DeBock
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John H. Bryant <bjohnorcas@...>
Great Job, Gary!!!
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Here is a link to Gary's photos. The last two are of the 7600-GR. and here is a link. http://ph.groups.yahoo.com/group/ultralightdx/photos/browse/9d45 **GARY** Would it be possible for you to give the turns count information in the caption of the photos.... With buying the rod from Amidon and the exact 40/44 Litz wire from Dave Schmarder, anyone ought to be able to do that mod without an LC meter, if they followed your turns count info. Fellas: Have you noticed that Gary continues to use pieces of the orange plastic builders' level??? That is likely the secret to success. Gary, is it from Home Depot??? :>) John B.
At 06:34 PM 7/28/2008 -0400, you wrote: Hello Guys,
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John and Others,
The Amidon 7.5" loopstick modification for the
ICF-SW7600GR is simple and straightforward, even for those hobbyists with
limited technical ability. A detailed file with "Heathkit-like
instructions" should be prepared shortly, including turn counts, part sources,
and photos.
As far as using parts of the builders'
levels as PVC mounting frames for the loopsticks, John, the original idea
was to have a black and orange color system for all the "monster"
loopsticks, in accordance with their scary, Halloween-like
appearance. Orange builder levels match perfectly with the black Amidon
bars, and they are very lightweight, fully insulating, waterproof, and even
somewhat shock-absorbing. Who could ask for more? :>)
73, Gary Get fantasy football with free live scoring. Sign up for FanHouse Fantasy Football today.
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maxyhopy
Hello Gary,
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I am very interested in modifying my SW7600GR. Could you tell me what size litz wire you used and also approximately how many turns you used in modifyoing your Sw7600GR ? Appreciate any help. Frank
--- In ultralightdx@..., D1028Gary@... wrote:
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Hello Frank,
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Thanks for your intererst in the Sony ICF-SW7600GR 7.5" loopstick modification. This project was designed (in July of 2008) to provide a very compact, sensitive SSB spotting receiver for Ultralight radio TP-chasing on ocean beaches, and was quite successful in this objective. A photo of the modified ICF-SW7600GR is posted at http://www.mediafire.com/i/?kyneobkgsk21n3c . On an Amidon 7.5" Type 61 ferrite bar (available from http://www.amidoncorp.com. for $20 plus shipping), on a base of J & J 2" waterproof tape (adhesive side out), wind a center large coil of 120 turns of 40/44 Litz wire (983 uh), and a separate, single turn of the wire 1/2 inch to the left of the large center coil. After recording the Litz wire color-coded connections to the stock loopstick, desolder the connections and carefully remove the loopstick (which usually needs some "persuasion" because of a serious amount of glue on the bottom). Install the replacement loopstick on the frame of your choice, and duplicate the original Litz wire connections to the new loopstick. You should enjoy a huge boost in sensitivity, making your tiny ICF-SW7600GR more than competitive with a stock ICF-2010 on both MW and LW. My original post on this project (from July 2008) is pasted below (minus the numerous ??? marks, which may make me seem more confused than I normally am :-) 73, Gary
-----Original Message-----
From: maxyhopy <fsphotos@...> To: ultralightdx <ultralightdx@...> Sent: Sun, Mar 27, 2011 10:58 am Subject: [ultralightdx] Re: Sony ICF-SW7600GR 7.5" Loopstick Mod Completed Hello Gary, I am very interested in modifying my SW7600GR. Could you tell me what size litz wire you used and also approximately how many turns you used in modifyoing your Sw7600GR ? Appreciate any help. Frank Hello Guys, Although it's a little too large to qualify as an Ultralight radio, the ICF-SW7600GR provides fairly competent MW performance in a compact, SSB-capable design. For those MW DXers unable to accommodate an ICF-2010 for space or financial reasons, this Sony portable would be perfect as an SSB "spotting receiver" for Ultralight radio transoceanic targets on an ocean beach... if only it had more sensitivity. Having had an unused unit sitting around since the Ultralight "Boom" started late last year (and faced with a situation where a multi-family vacation would make packing space extremely limited), there was a sudden compulsion to replace the stock 4.75" x .37" loopstick with a much more effective Amidon 7.5" x .5" loopstick wound with 40/44 Litz wire. This MW frequency-optimized combination has provided an incredible sensitivity increase in the SRF-39FP and Eton E100 Ultralight models (enabling both to receive Australia signals at Grayland), and I was curious how far it would boost the performance of this compact SSB portable. The ICF-SW7600GR has a stock loopstick very similar to that of the ICF-2010, in which a fixed larger center coil is mated with a much smaller tickler coil, used for adjustment of the unit's spurious signal rejection. As such, the instructions for "supercharging" the ICF-2010 (currently posted in dxer.ca's Ultralight File section) are electrically applicable to the ICF-SW7600GR, although the lsmaller unit has a large coil inductance of 983 uh, and the stock loopstick does not have a snap-out design like the 2010, requiring the hobbyist to use a moderate amount of effort in separating the glue at the base of the ferrite bar. The performance improvement for this $30 modification has certainly exceeded expectations! When the stock unit was checked against a stock ICF-2010 prior to modification, it was clearly inferior in sensitivity on all frequencies. The stock 2010 was far more effective in digging out weak daytime fringe stations, with or without the Synch function. After the ICF-SW7600GR received the Amidon 7.5" loopstick, the situation was completely reversed. The still-compact SW7600GR now clearly outperforms the stock 2010 on all MW frequencies-- low, middle and high band. High-band performance is particularly striking, with Synch lock performance on a 1610 TIS station completely inaudible on the stock 2010. This has been achieved despite a very modest expenditure for parts (about $20 for the Amidon ferrite bar, and under $10 for the Litz wire and other items). The modified SW7600GR is also much smaller and lighter than a stock 2010, providing a very practical, compact SSB "spotting receiver" for Ultralight TP/TA chasers. Two pictures of this modified ICF-SW7600GR have been uploaded to the "ultralightdx" Yahoo Group site, in the "Roll Your Own DXing Monster" album. It is hoped that various MW DXers will feel motivated to modify their own ICF-SW7600GR units, and obtain the outstanding MW performance possible with this model. 73, Gary DeBock
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