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SB 200 and TS 480SAT Compatible?

Discussion in 'Amateur Radio Amplifiers' started by NT5T, Jul 20, 2013.

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  1. NT5T

    NT5T Ham Member QRZ Page

    If ignorance is bliss, I am among the happiest of hams! 25 years off the air. Just purchased a TS 480SAT and am wondering what is involved in using a SB 200 or what fairly low cost amp is the best to work with the TS 480SAT?
  2. WX7G

    WX7G Ham Member QRZ Page

    A decent low cost amp (new) is the Ameritron AL-811 for $730 (DX Engineering) and it can be keyed directly with the TS-480. To tune the amp you will need an RF wattmeter.

    I believe the SB-200 keying voltage exceeds the capability of the TS-480SAT. An Ameritron ARB-704 keying interface ($60) will allow the TS-480 to work with the SB-200.
  3. K9STH

    K9STH Ham Member QRZ Page

    Or, you can use a 12 VDC relay from Radio Shack to key the SB-200 and save almost $50!

    Glen, K9STH
  4. WA9WVX

    WA9WVX Ham Member QRZ Page

    Hmmm, Glen I wonder you would connect the ALC line between the transceiver and the RF Amplifier and make it work?

  5. KM3F

    KM3F Ham Member QRZ Page

    If you look at the SB200 keying circuit, it is derived from 120vac source that is rectified to DC.
    Grounding the key jack not only grounds the relay but that ground is connected to the amplifier tubes grid circuit.
    Use a 12 v dc relay in a small project box to make the ground for the amplifier.
    Provide 12 volts from your 480 supply to the relay and use a cable from the 480 to operate the outboard low current mini relay.
    Use all shielded cables, RCA jacks and your radio is isolated from the amplifier keying circuit.
    The ALC should work as is unless there is a level control issue that needs to be addressed, then you would uses a pot to control the feedback level..
    Good luck.
  6. K9STH

    K9STH Ham Member QRZ Page

    The ALC should work. However, like 3F says, you might have to make some slight modifications.

    I use my SB-200 with a Heath SB-401 and the ALC circuits are designed to "work together".

    Glen, K9STH
  7. WA9WVX

    WA9WVX Ham Member QRZ Page


    SB-200 and SB-401 Heath Kits are from the same period in time as to when they designed so they better work together. Where as Kenwood TS-480S has been designed in the 21 st century and uses a lot lower voltage and current fed back from the SB-200's ALC circuit versus a solid state HF RF amplifier. This is why Ameritron started manufacturing the ARB-704 Interface Boxes and matching cable kits that plug into each piece of equipment. There's less likely hood of frying the ALC circuit in the solid state transceivers when using a tube amplifiers. One thing everyone has to keep in my mind is, most of the new hams entering this hobby don't possess much electronic background, don't seem to want to homebrew or experiment, they only understand "Plug & Play." Heaven help them if something releases the magic puff of smoke while operating and the radio quits working, they'll be looking for a radio repair person on the internet to troubleshoot the equipment remotely and for free! I'm sorry it doesn't work that way in real life.

  8. NT5T

    NT5T Ham Member QRZ Page

    Unfortunately, after more than 25 year off the air, I am as one of the new hams entering the hobby. My first rig was a Knight T-60 with a Navy RBD 40/80 meter receiver and a long wire tuned with coils and a neon bulb placed just under the coils . . . bright bulb, good signal, dull bulb, keep adjusting the coils. My first amplifier was a home-brew a friend had covered with a tarp in his barn. My extra class license came only after much hard work trying to understand enough electronics to pass the test after three tries and mastering the 20 WPM code. In the presence of the FCC examiner I was so nervous I couldn't even read my own transcription of the 20 WPM code test the first time and neither could he. My call is not a vanity call but one that I was very grateful to receive--North Texas Five Texas. My interest in radio came as my WWI Navy radio op father told me that he was able to do 30 WPM hand-key and was on board ship for the first ship-to-ship radio communications. I have not kept up with the developments in ham radio and probably know less than the new hams you describe. If my request for help is out of line, I did not intend it to be. There was a time when I spent a lot of time enjoying CW with my Yaesu FT 101, that home-brew amp and a 4 element Swan tri-bander up about 56 feet on an old electric utility pole. Now I am in a HOA and very limited with what I can use. I am looking forward to getting back on the air again. But, you are right--a puff of smoke would bother me. I'd do my best to find out what happened, but would probably have to take it to someone and gladly pay them for what I am now unable to do.
    Bill, NT5T (Originally WN5QBE, WA5QBE)
  9. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    If you already have the SB-200, I'd just modify it for low voltage keying and use it; but if you don't already own it, something like an AL-811H is likely a better deal and requires no modifications or interfaces to just use it with the TS-480S.

    Not sure if the SB-200's ALC is compatible with a TS-480S or not: It might not be, but no big deal since the 480S can probably not overdrive an SB-200 no matter what you do. The SB-200 was designed to be used with the Heath rigs of that era which all ran 100W or more output power from a pair of 6146s; the TS-480S can't exceed that, and 572Bs are very forgiving. If you "load" the amp properly, the grid current will remain low and nothing will be overdriven.
  10. NT5T

    NT5T Ham Member QRZ Page

    I don't have any amplifier at this point. My wife thinks a "new" would be best for me since I'll probably have it for a long, long time--that is, if I live that long! Thanks for all the info and support. I spent some bucks trying to get someone to look at my FT 101 and they said it probably was not worth fixing. I'm going to find someone in the DFW area and get a second opinion. It was sure good for a lot of contacts years ago.
    Again, thanks.
  11. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    The FT-480S will blow away the FT-101 in every single respect. FT-101s date back to the early-to-late 1970s so they're all pretty old.

    It's like trying to restore a car from 1975: Can be done, if you have the time and money.:eek:
  12. WA9WVX

    WA9WVX Ham Member QRZ Page

    Bill, Steve & Glen,

    Perhaps you didn't realize that the Kenwood TS-480S transceiver with a high current +13.8 VDC Power Supply is capable of 200 W PEP RF Output by itself. I my book that would easily overdrive a SB-200 Linear Amplifier hands down. It might look like a small transceiver but the Kenwood engineers incorporated some healthy Final transistors into that package.

    Bill, my comments were point at the CB crowd coming up to the Amateur Radio bands, you can almost tell by readfing some of their questions and comments especially if they, I say have one by three call signs. For the most part hams that have one by three call letters wouldn't be asking how to tune a transmitter and/or a linear amplifier because they were around when all of the older equipment was nothing but tubes.

    You had to know how to operate the T-60 transmitter to dip the Grid and peak the Final for resonance and most of the time you had a VSWR bridge in the circuit to watch your signal. Bill, just because you've been away from Amateur Radio for 25 years, you still under the basic electronic theory and you might be a bit rusty on your CW speed but it all come back to you in time, similar to riding a bicycle.

    I remember something like 30 years ago there were a bunch of us in the Chicagoland area operating 2 m SSB and this one night one of the ops who was trying to get his WAS for 2 m via Moon Bounce was operating his homebrew 1500 W PEP RF Amplifier. Anyway, the Plate meter stuck for some reason and instead of tapping on the Meter movement, the guy opened the top of the Bud cabinet while he was On-The-Air, probably thought he could reach into the RF Deck and grab the meter leads, unfortunately he grabbed the wrong wire that lead to the Plate of the 8877 RF tube. I've never heard such a loud scream come over the airwaves as that night! That guy was very lucky he didn't kill himself when that happened. I never did see his amplifier but I can tell you, anyone who builds a high power RF amplifier and does not use the proper shielding around the RF cage almost deserves what happens to them while they're operating! In fact, if you think back 25 or 30 years ago, in the QST magazine, they always had these Icons with the saying "Switch to Safety." The guy should have never opened the amplifier while transmitting, he should have shut the unit off first before poking around in the RF box. The rest of us always had something to talk about at the local hamfest about this individual. An 8877 can have as much as 4000 V DC at 1 A applied to the Plate of the tube .... that's real power on transmit and it's enough to kill a person if they're not careful. If you're ever troubleshooting a tube RF amplifier, ALWAYS put one hand in your pocket away from the metal chassis so you don't accidently complete the electrical path to ground if you happen to touch or bump the High Voltage while the unit has the primary power applied.

    Good Luck with your ham station!

  13. WX7G

    WX7G Ham Member QRZ Page

    The reason I recommend the AL-811 amp over the AL-811H amp is reliability. Modern 811A tubes are not especially reliable and the AL-811H, using four tubes rather than the three in the AL-811, will have 33% more tube failures.
  14. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    No it can't. That's the TS-480HX, not the TS-480SAT. The TS-480SAT is limited to 100W PEP output maximum, and has only "half" the PA stage that the HX has.
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