Yaesu FT-900 to Yaesu FL-2100B amp wiring questions?

Discussion in 'Amateur Radio Amplifiers' started by KE4CIJ, Jun 8, 2014.

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  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The caps will eventually fail, so it might be worth replacing them. However I don't know why that would take weeks, it usually takes an hour or two, and right back on the air.

    Does take some good soldering skills and a few tools.

    Despite that the FL-2100 wasn't a great design, there are lots of them on the air. They should have included grid current metering (the easiest way to "tune up" a tube amplifier) and used some better parts, but still they sold thousands of them. Sounds like you got a good one that wasn't abused, and that helps a lot.

    If you decide to sell it, I'd replace it with a newer design, like an Ameritron AL-80B. Small footprint, not terribly heavy, but a very robust amplifier that rarely fails.
  2. KE4CIJ

    KE4CIJ Ham Member QRZ Page

    Well, the reason for it taking weeks is simply a health related issues, I have good days and bad. Some days are worse than others but I know I can do it. I have re-capped a lot, and I mean a lot of equipment.

    Okay so here's what I plan on doing, upgrading the caps, all the electrolytic if possible and upgrade the parasitic chokes on the tubes. Since I have had it, I have just let it sit on for several hours. Being I have No idea when it was last used, I thought just letting it idle was a good thought and so far it seems pretty stable. I have kept close eye on it. I replaced the mains cord because the old one was pretty cracked up. I also used a newer type polarized plug with ground and chassis ground it as well. Maybe a bad idea but anything with tubes in it, I have always done that for safety sake, My safety! LOL!

    As for this relay added into the amp that I was reading about, How Hard of job is that? I'll have to go back and get a better idea of why this is added but I am curious about that. I'd like to do that also, but I wonder where I can get the parts and what parts is needed?

    One major concern I have is the Don't do list with this amp. What are your thoughts on things you shouldn't do with this amp? From reading I gather AM operation is something to avoid with this amp in factory shape without mods. I have no intentions of operating the amp on AM or 10 meters. My real intent was 15 and 20 meters where it seems to shine some and 40 meters.

    The do's I get, but I was reading things people do by mistake which causes the amp to fail and in some cases, when the amp fails it kills your rig in the process. So what is the best thing to do to protect your rig?

    That concerned me because my primary rig is a great little FT-900 and they just do not build rigs like that today. That rig has been a really good here at my shack. Even though when I got it, it had some issue with the Microphone plug and not wanting to work with other mikes. I had that repaired and I have owned that rig for around 10 years, wouldn't take $1000.00 bucks for it today! So whatever I can do to protect it I want to do it...

    What I would really love to own is the Ameritron 811H. That is what I wanted when I got this, but the price for this one, I just couldn't turn it down the condition of this amp just floored me. It is really clean and the guy that owned it was a very very picky man.

    Last edited: Jun 15, 2014
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The AL-811H is always questionable because of tube quality. Old RCA 811As made in the U.S. from the 1930s through the 1970s were great. Now, they're all made in China and according to RF Parts, Ameritron and everyone buying quantities of them, they vary from "okay" to "terrible," and a lot of them fail in test. Unfortunately, same goes for 572Bs.

    I don't know what the relay mod is. Using a grounded power cord is always a good idea.

    I had an FT-900. In fact, I wrote the Product Review for it, which was published. It was the first rig I'd ever used (or even seen) with a detachable control panel, and I did get the optional separation cable for that, and used it mobile for years.

    It was an excellent, easy-to-use rig. Modern day rigs with detachable front panels are very cute, but none of them are as nice as the FT-900.
  4. KE4CIJ

    KE4CIJ Ham Member QRZ Page

    Go about half ways down the page, it shows a relay used to correct something about Bias issues with the 2100.

    You know what I really like about the FT-900 besides it being just a great little radio, is that HUGE HINK SINK! Like the 2400H made back in the day, that was an awesome 2 meter radio and built like a tank. One problem was that Crappy VFO they used back then ruined the 2400's and made them quickly get issues. I think at one time a kit as out to fix that but I never got it so I don't know if that worked or not. I would love to get hands on a kit and repair my old 2400H it was a seriously good mobile built out to Military Spec. Huge Hink sink on those old radios too.

    These newer rigs like the 857 are not nearly as well made as the 900 or 2400 and they just do not hold up over time. They're made with cheaper parts, the plastic cracks and often goes brittle and falls apart. The separation kits are really skimpy made and do not hold up or that has been my experiences with several. I have an 857 that has never been used very much at all. It's basically a new radio because air time has been very limited, that thing has gone deaf sitting on a shelf! What a let down!

    Check out that relay mod and see what you thing on that?
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Why not sell the 857D? "Backup" rigs shouldn't be required, when you have a good one.

    What I like about the FT-900 is all the controls are on the panel, so you needn't resort to menus to make adjustments. The 857D is menu-deep and highly menu-driven and if you don't use it a lot, you'll need the manual to even use it.

    With the 900, I took delivery, put the manual in a drawer (never even looked at it), connected it up and started making contacts...thousands of contacts...I don't think I ever took the manual out of the drawer.

    I don't know anything about the relay mod and have never done it; probably not necessary and I wouldn't recommend anything that isn't necessary.
  6. KE4CIJ

    KE4CIJ Ham Member QRZ Page

    Thanks, I saw that and was like what? Read a little more and it sounded like a good idea I suppose so I was like okay maybe I should do that.

    I guess whomever came up with the mod knew what they wanted to do. As for the 857D, I would love to sell it or trade it for an Ameritron. I really have no use for it, I have the 900 and I have an 847, Icom 706MKII they're all older rigs. I really like the 847 for it's ease of use, I haven't used that rig in about 3 years due to being sick. But I got it out, hooked it up and yes it took me a few minutes to get used to it but It was like seeing a lost friend. Now, like you the 900 is an awesome rig, so very easy to use, about a 1 minute of checking it out you pretty much get how it works. No need for manuals unless you want to do hidden features, if you've done those enough with the 900 you don't even need it then.

    Yes it might be time to get rid of some other rigs I have a few, at one time I had a mobile in both the cars. I had the ham shack rigs, and the 847, I like for it's ability to go 6 meter all mode.

    You know which rig out does the others without guessing!

    The FT900 sounds better than any rig I have. I have talked to stations far away and get better results with the 900.
    The 847 has a desk mike, the 900 a hand mic. The 900 has more punch with processing than does the 847.

    I have talked to stations and just for fun, switched radios and ask which sounds the better, in every case they would say the 1st rig which was always the 900.

    Hands down it blows the others off the map with audio and punch. It's not a bad CW rig either!

    The only advantages the 847 has over the 900 is the fact it does 6 meters, also the fact it will work satellites, I used to be really into that years ago.

    Getting back to the amp, somethings I see on all the mods, I think maybe it was a good idea. Example, capping is a good idea in any 30 year old tube equipment or at least I believe it is. I also think putting grounded electrical cords on tube stuff is a good idea. The parasitic resistor upgrade I can see that because of the heat on the older ones. I can also see doing some other change outs. But really some of this other stuff I read about, I just don't see it, the Japanese aren't by any means slack in electronics. If those amps were that bad, they wouldn't have lasted in original form for 40 years, yes they have issues we know that but over all they're exactly what you pay for a cheaper amp.

    Some folks swear by them, others don't.

    A lot of folks blame the amp when the amp isn't the problem. Some blame the amp when tube have been the troubles too...Hard to get a good 572B these days...if you have some good ones, you better take care of them!

    Okay..ranted over!


    Have a good fathers day!

    God Bless!
    Last edited: Jun 16, 2014
  7. KE4CIJ

    KE4CIJ Ham Member QRZ Page

    We had a lot of storms today so I was late getting on the air. A lot and I mean a lot of intentional interference was plaguing the net I check into. I tried several times to let the net control know I was on, was there if they needed a relay. Tried for over 30 minutes, gave up and then thought well I do have the amp. Haven't tried it before this evening. So, went down the band and because it was already hooked to the antenna, check the frequency made sure no one was there. Started Tune up procedures and there it was..I hope I tuned it correctly I was pretty nervous, been years since I tuned up an amp! I mean years! So went back up the band, waited to make sure no one was in dire straights touched up the tuning again about 30 seconds of tweak and checks...

    The interference came back about S9 dead on that frequency, I could barely I Mean barely make out the NET Control. I called back to him and by grays he heard me. Made me right happy! I had pulled back my rig to about 80 watts and wasn't driving that little amp that hard. Was getting about 575 watts on peaks and when I used the High on my microphone It was clipping 600 watts on peaks on the meter but I was driving it with about 95 watts then.

    Okay let me ask, on the tuning, I just want to make sure I was close.
    1st thing was to make sure the antenna was tuned with the rig low power.
    2nd was to check it on full output from the rig and tweaked it for best tuning on the tuner.
    3rd, set rig back to about 20 watts.
    Now I let the amp warm up about 30 mins prior to tuning it. That comes more from habit than anything else. That habit comes from about 20 years ago.
    4th, I set the Load to preset according to manual.
    5th, I made sure SW was in IP
    6th, SW to operate
    7th Set Plate to dip lowest on meter,
    Checked it twice
    8 powered rig to about 45 watts,
    Again adjusted load,
    9 dipped plate to lowest
    and repeated adjusting rig and plate/load until Amp meter was just bumping .5 which is supposed to be full out put, this part I was careful not to go past .5 so I just let it get right before it on the meter.

    then I backed the rig back to about 80 watts, left the amp alone but rechecked everything 2 times to make sure I as in margin with the manual. I got excellent reports, from the net control and others down the band. When I changed frequencies I touched up every thing. I noticed that it really did not change a lot if I stayed within 5 kilo's of my frequency of choice but I tweaked it anyways.

    How badly did I do?
  8. KE4CIJ

    KE4CIJ Ham Member QRZ Page

    After I read this, after I think about it, maybe over thinking it a bit but I think I loaded it incorrectly. Reason being I watched a video on tuning a few minutes ago, granted I was close to the video, but I was using Plate to dip, the guy in the video seemed to be using load to get the dip. I was using both, I think...I should have never watched that video and just did it the same way I did my other amp 20 years ago. Yes, I'm a tad OCD over this thing a lot over others, but this has really kept me up lately.

    A serious question, should you see a voltage dip when keying at full load? I am sort of worried about the mains line being under rated. I was checking that and that line has lighting in the basement on it also. It has one wall outlet, and 2 lights on it, plus the amp, when I keyed the amp using CW the light dimmed slightly. Reason I asked this is because I saw a pretty good drop in voltage on the amp, when I keyed it using CW, not as much on SSB but a pretty good drop on CW.
  9. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Adjusting an antenna tuner works at any power level, so always use the lowest power you can, and still get an effective SWR reading. No reason ever to adjust the rig up to full power to "re-tweak" the tuner, because if it's adjusted properly at 10W, it will still be adjusted properly at 100W. Re-tuning just wastes time and creates more interference on the bands.

    The amp takes 1-2 seconds to fully warm up. Waiting 30 minutes just wastes electricity. Also, I recommended adjusting the rig to about 50W output, not 20W. Reason is this: If you tune up the amp with 20W drive, you'll have to re-tune it quite a bit at full power, so the 20W tune up just wastes time and power and creates more interference. It's fine to start right out with about 50W drive.

    That all "works," but I recommended ignoring the Ip other than to watch that it doesn't go over 500 mA (for very long), and tuning up using the output Wattmeter. Peaking the PLATE and LOAD for maximum output power is exactly as effective as "dipping the plate current," maybe more effective, and certainly very easy to do. I'd just do that. I watch Ip only to assure it doesn't get too high, and after tuning should be about 500mA.

    You can change frequency much more than 5 kHz before re-tuning. On 40m, "one" tuning should hold for about 75-100 kHz. On 20m, "one" tuning should hold for probably 100-150 kHz. On 15m, probably 150-200 kHz; on 10m, probably 250-300 kHz. No reason to "re-tune" every time you change frequency; again, wastes time and power and creates needless interference.

    With that amp, the "more often" you tune up, the shorter the operating life of the tubes will be. Once tuned, you can transmit on SSB forever without wearing anything out; it's the "tuning" that can do damage. I'd recommend "practice tuning" into only a dummy load and not an antenna; and keep "key down" tuning times short, like ten seconds. Just peak for maximum output (two knobs, takes five seconds) then observe Ip to make sure it's not too high (>500 mA). Done!
  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    You'd never use the LOAD to dip, and to me, even using the PLATE to "dip" is a silly waste of time. Tune up for maximum output power on the wattmeter, which accomplishes the same thing and is easier to observe. I'd ignore most of the videos on the internet, about 90% of them are really silly and sometimes horribly misleading.

    You'll know if the line doesn't have enough power when you trip a circuit breaker.:p The high voltage reading on the amp should definitely dip when transmitting, and about a 300V drop from "unkeyed" to "key down, full power CW" would not be unusual.
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