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#1
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![]() just aquired a used radioshack DX 398--works well except the sensitivty is low (sounds like an attenuator is switched in!!)...are there things to check/modifications etc to improve the sensitivity of this radio? i am running the attenuator knob at the full gain posiiton. radio wld be fantastic IF I could improve its sensitivity/gain. As stands--my SONY 7600/YachtBoy 400 etc absolutely blow it away..i dont think this is a normal situation, so i suspect the dx 398 has a problem. thanx for all suggestions/links to web sites dealing with this issue. ed s |
#2
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This may sound like a stupid question but...
You DO have it turned ON all the way and not OFF? COUNTER-CLOCKWISE is on full... "Bunia3" wrote in message ... just aquired a used radioshack DX 398--works well except the sensitivty is low (sounds like an attenuator is switched in!!)...are there things to check/modifications etc to improve the sensitivity of this radio? i am running the attenuator knob at the full gain posiiton. radio wld be fantastic IF I could improve its sensitivity/gain. As stands--my SONY 7600/YachtBoy 400 etc absolutely blow it away..i dont think this is a normal situation, so i suspect the dx 398 has a problem. thanx for all suggestions/links to web sites dealing with this issue. ed s |
#3
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It also 'clicks' to the full sensitive setting.
Ken "Jim Hackett" wrote in message ink.net... This may sound like a stupid question but... You DO have it turned ON all the way and not OFF? COUNTER-CLOCKWISE is on full... "Bunia3" wrote in message ... just aquired a used radioshack DX 398--works well except the sensitivty is low (sounds like an attenuator is switched in!!)...are there things to check/modifications etc to improve the sensitivity of this radio? i am running the attenuator knob at the full gain posiiton. radio wld be fantastic IF I could improve its sensitivity/gain. As stands--my SONY 7600/YachtBoy 400 etc absolutely blow it away..i dont think this is a normal situation, so i suspect the dx 398 has a problem. thanx for all suggestions/links to web sites dealing with this issue. ed s |
#4
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Does anyone know what device functions as the first RF amp in this radio?
Most likely some kind of FET...That would be a good place to check if you are convinced the sensitivity is down. Some models of radios had FET RF amps that were susceptible to static damage. "Bunia3" wrote in message ... just aquired a used radioshack DX 398--works well except the sensitivty is low (sounds like an attenuator is switched in!!)...are there things to check/modifications etc to improve the sensitivity of this radio? i am running the attenuator knob at the full gain posiiton. radio wld be fantastic IF I could improve its sensitivity/gain. As stands--my SONY 7600/YachtBoy 400 etc absolutely blow it away..i dont think this is a normal situation, so i suspect the dx 398 has a problem. thanx for all suggestions/links to web sites dealing with this issue. ed s |
#5
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![]() "Bunia3" wrote in message ... just aquired a used radioshack DX 398--works well except the sensitivty is low (sounds like an attenuator is switched in!!)...are there things to check/modifications etc to improve the sensitivity of this radio? i am running the attenuator knob at the full gain posiiton. radio wld be fantastic IF I could improve its sensitivity/gain. As stands--my SONY 7600/YachtBoy 400 etc absolutely blow it away..i dont think this is a normal situation, so i suspect the dx 398 has a problem. thanx for all suggestions/links to web sites dealing with this issue. IMO, there's something wrong with the radio if those other two "absolutely blow it away." Regardless of the merits of the three--and the standard knock on the 398 is an alleged lack of sensitivity on the whip--there should not be -that- big a difference. These guys reportedly do a great job and you may get some ideas about mods he http://www.radiolabs.com/products/re...s/super909.php I would check the Yahoo 398/909 group as well. As I remember there's a lot of discussion of mods there as well. |
#6
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There may not be anything wrong with yours. The 398/909 is pretty
deaf off the whip. Try an external antenna of even moderate length, 20 ft or so into the external antenna jack. You should find that the radio really comes alive. If not, then you have a problem. The 398/909 is super with a short external wire. This is why I think it is great mini-desk top radio but not so hot as a travel portable. Also, the extremely short battery life on this radio makes it a poor choice as a portable. Feed it a little wire and an AC adapter and you got a great set up |
#7
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Feed it a little wire and an AC adapter and you got a great set up
Shoot, I run a at least a 120ft.wire sloper (rf free environment) on it and it's just fine. ~*~*Monitoring The AirWaves~*~ *****GO BEARCATS***** Hammarlund HQ129X /Heathkit Q Multiplier Hammarlund HQ140X Multiple GE P-780's(GREAT BCB Radios) RCA Victor *Strato- World* RCA Victor RJC77W-K(Walnut Grain) 1942 Zenith Wave Magnet 6G 601M Cathedral/ Ross#2311/Rhapsody-MultiBand DX100/394/398/399/402 OMGS Transistor Eight/Realistic 12-1451 Henry Kloss Model One/Bell+Howell ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* Alpha Delta DX Sloper 57ft. 600ft. 12AWG. (non-terminated) 120ft. 12 AWG Sloper 2 Radio Shack Loop Antennas Radio Shack Amplified Antenna 30X30 DiamondLoop(six section 830pf Cap) * Diamond Loop mounted to Lazy Susan TurnTable* *21/2X2ft.FiveSpoked~Penta-Loop~PancakeLoop* |
#8
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yeah. The little wound transformer transplant from Frank C. fixes the whip
impedence matching problem and makes the whip real sensitive. There is also a blocking transister you can remove to increase all AM sensitivity, including mw reception. It won't resist interfering FM bleeds into the SW band as well though.I have both mods on one 398 and just the transformer mod on the other. I tend to like just the implant the best. You can find these mods by searching. ....Hindsight Band |
#9
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Sangeans in general are known for this. They work better than most though
with an external antenna. "Bunia3" wrote in message ... just aquired a used radioshack DX 398--works well except the sensitivty is low (sounds like an attenuator is switched in!!)...are there things to check/modifications etc to improve the sensitivity of this radio? i am running the attenuator knob at the full gain posiiton. radio wld be fantastic IF I could improve its sensitivity/gain. As stands--my SONY 7600/YachtBoy 400 etc absolutely blow it away..i dont think this is a normal situation, so i suspect the dx 398 has a problem. thanx for all suggestions/links to web sites dealing with this issue. ed s |
#10
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Rick W 999 wrote:
yeah. The little wound transformer transplant from Frank C. fixes the whip impedence matching problem and makes the whip real sensitive. There is also a blocking transister you can remove to increase all AM sensitivity, including mw reception. It won't resist interfering FM bleeds into the SW band as well though.I have both mods on one 398 and just the transformer mod on the other. I tend to like just the implant the best. You can find these mods by searching. ...Hindsight Band I did the R43 resistor mod' (removal) and the homemade impedance matching transformer for the whip, in that order. If I had known how well the transformer works, I wouldn't have bothered removing R43 too. Someday I'll put it back. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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