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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W4FCC on March 08, 2007, 09:57:04 PM



Title: TS-520 AM Mod- Anybody Actually Done It? Worth the trouble?
Post by: W4FCC on March 08, 2007, 09:57:04 PM
Yes, I know this borders on sacrilege with a Ranger in the closet that hasn't been powered up in 15 years and needs caps, but that may end up being a Retirement Project.

 My aging 520SE is still plugging away, and I've been mulling over the AM mod for a while now.  The only part for it I don't have in the junkbox already is the transformer, may have to order that since there are very few places nowadays you can just walk in and buy stuff like that.

  Anybody done this to their rig or heard one on the air?  What did you think of it?

  Thanks,

   Rick


Title: Re: TS-520 AM Mod- Anybody Actually Done It? Worth the trouble?
Post by: K1KFI on March 08, 2007, 11:00:07 PM
Rick,

 I have done the mod on a ts-520 s...made nice carrier with it...
then decided that there was no where to go with it...now it stands as my ssb staion with enhanced audio...bout all its really worth!..nice sounding tho..open up the butterworth filter on the MAO. Still its only about 2.8kc...my advice, go for something that straps!   see you there!


Cliff
K1kfi


Title: Re: TS-520 AM Mod- Anybody Actually Done It? Worth the trouble?
Post by: Pete, WA2CWA on March 08, 2007, 11:14:02 PM
Well, since you didn't identify where this mod is, I'll assume it's the one floating around the various "mod" sites.

Ya got to screw around with the balanced modulator and the audio circuitry on the transmitter side and then add some type of AM detector, diddle with the AGC, and probably add an AM filter. Add a relay of two to switch this stuff around if you want to retain the SSB and CW functions and, in the end, ya got a 20 to 25 watt pseudo AM rig. I don't see the point in the effort.

If you want AM, SSB, and CW receive and transmit functions in one box, sell the TS-520SE and buy a Yaesu FT-101 series rig, or a Kenwood TS-510, TS-900, or the 599 Twins(2 boxes + a transceiver cable). There are newly licensed Generals that would probably jump at the chance at buying the rig. 


Title: Re: TS-520 AM Mod- Anybody Actually Done It? Worth the trouble?
Post by: W4FCC on March 09, 2007, 12:24:34 AM
Thanks Fellas

 I may give it a shot, I'm mindful of its limitations.  I kind of like the old hybrid rig, was planning buy a new HF rig and seek out a boatanchor rcvr to match up with my old Ranger this year-- but had to sink $5600 into a new engine for the family car--thus the interest in putting the 520 on AM for the short term.  I figured it may not sound any worse than any of the other 25 W pseudo AM transmitters I'm hearing on 75.  Actually, most of them sound better than a prominent "real" AMer who usually has a very loud signal into my area, but always has a noticeable 60 cycle hum underneath his audio, despite his impressive audio chain (and website).

But right, I didn't spec which mod-- this one's just for the xmit, bypassing the balanced mod with a relay and routing the speech amp to the RF driver via a transformer.  Still have to zero beat everybody, but I've been doing that listening to the nets anyway, and the 520 does a surprisingly good job on rcv with that.  Not an optimum arrangement by any stretch, but cheap-- and that's the name of the game right now as far as playing radio at my house.

                Thanks,

 
                   Rick
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands