Yaesu FT-101 Tube Question.
SAM
You are going to have to check with used and NOS tube dealers. I don't believe
that 6JS6s are made anymore. You will have to pay up for them, too. Probably
between $25 and $50 each. If the tubes are different brands, you may have some
trouble neutralizing them. If the tubes are good, you should see around 85
watts on tune up, give or take a few, and 120 to 150 PEP on SSB.
John Phelps
Was wondering about this nuetralizing process. Have heard allot about it
but don't really know how to do it. Could you explain?
Thanks again,
John Phelps
Mike Rofon
Some manuals really make it seem complicated. Basically you adjust the
neutralizing cap so that the current dip coincides with max out. You
don't need to lay on the key to do this. Repeat tweak and retune till
you hit the right spot. Dummy load required :-) If it takes more than a
few minutes, something else is wrong.
-Bill
SAM
Its been more than 20 years since I've done it and I can't remember that far
back. Neutralizing neutralizes the interelectrode capacitance in the tubes
thereby minimizing the RF feedback from the plate to the grid. This feedback
will cause the tube to self oscillate if not neutralized. My recollection is
that you neutralize by minimizing the plate current while maximizing the screen
and control grid current. But refer back to my first statement.
Scott M.
Scott Dorsey
John Phelps <chili...@webtv.net> wrote:
>I just got this Yaesu 101 with the YC-601 frequency counter. The thing
>lights up and receives real well but the guy I got it from says the
>tubes need to be replaced so I haven't transmitted on it.
>I pulled the tubes out and the two final tubes (Labelled 6JS6A Toshiba)
>have what looks like some glass rattling around inside them. The driver
>tube (Labelled 12BY7A) seems fine.
>Question is where can I get these tubes?
12BY7 is a video pentode. It's available, but they are probably fine.
The 6SJ6 is a sweep tube. Good luck finding any, but try the usual
tube dealers (ESRC, Triode Electronics, Antique Electronics Supply).
>After replacing them what will be the output wattage of this unit?
About half of what it's rated if you want those finals to last.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Roger Halstead
news:3C9AB088...@netscape.net...
As you say, it should be quick and easy.
I had a 101B and although I used what ever was handy for tubes, I never had
to reneutralize the finals.
That rig damn near electrocuted me though.
Watch out for the AC power connector on the back of the chassis.
Mine had an extra bit of solder on the one lug (from the factory).
Even though the rig was grounded, there was enough resistance in the ground
that the coax shield out at the 1/4 wave vertical was hot. That braid also
tied directly to an 8' ground rod at the base of the vertical.
Several of the radials (bare #12 copper) had come loose during the winter,
or spring. I picked one up and pulled it tight and bent downt to stick the
end back into the ground. As soon as my knees touched the wet ground that
wire grabbed me but good. I rolled backward and as soon as my knees broke
contact, I threw that ground wire.
I took my Simpson, stuck one lead in the ground at the ground rod and the
other into the ground as far out as the length of the leads would allow. I
measured 90 volts AC.
--
Roger (K8RI EN73)
WWW.RogerHalstead.com
N833R, World's Oldest Debonair? S#CD-2
> -Bill
>
Aaron H. Voobner
Hm. "Chilin Vilin"...no callsign...only concern is "watts out".
Freebander?
Aaron H. Voobner
I was wrong. He's not a freebander, just a CB outlaw.
----------
Thursday, January 24, 2002 11:07 PM
I hooked up my cousins set up and am having a bad problem.
We hooked up the radio which is a old realistic 40 channel a boomer
125 amp and a 102 inch whip on a 1984 chevy van.
Got it all hooked up and didnt like the swr but couldnt seem to get
swr below 2.0. The radio worked fine without the amp on but as soon as
the amp is turned on and radio keyed nothing would happen. I could
hear the relay in amp click but no power output.
This same set up use to be hooked up in his 1969 Ford pickup without
any problems but the swr was like 1.4.
Anyway after all this I just took the boomer 125 out of his van and
hooked it up to a battery connected to the base station to see if it
would work in the garage. Well everything works fine. When in the
garage it deadkeys good and swings forward.
Then I took my palomar 250 out of the garage and hooked it up in van
just to see what would happen and it worked fine. So what is going on
here?
One amp will work good but the other wont key up at all.
Just to let you know there is 10 gauge wire coming from the battery to
amp which is about 6 or 7 feet long. From radio to amp is a 2 foot
jumper then from amp to antenna is a 20 foot piece of coax.
The antenna is mounted on the top center of van. It has the mount
where you have to drill thru the roof.
Well hope someone can help. Thanks in advance,
John Phelps
RCI 6900Fhp
Palomar 250
Wilson 1000
27.455 LSB
909 John Riverside CA.
-------------------------
John Phelps
John Phelps
Lionel Sharp
follows:
160 125 Watts
80 190 Watts
40 170 Watts
20 150 Watts
15 125 Watts
10A 100 Watts
10B 100 Watts
10C 80 Watts
Perhaps you can get more power with new tubes but you would not notice any
difference at the receiving.
Best of luck in obtaining Toshiba 6JS6 tubes for the final, they would be
very hard to locate and of course expensive. Some other brands (not all), I
believe, are a little taller which means you may not be able to put the top
back on the P.A. enclosure so check out the size before you buy. Remember
size does count.
Ideally the 12BY7 should be made by Toshiba. They were made to pretty tight
specifications and the driver stage is neutralized with a fixed value
capacitor. You may or may not have problems with other brands.
73
Lionel L Sharp, VK4NS
Grey Fox
vk4n...@ozemail.com.au wrote on 3/24/02 8:37 PM:
And remember to find where to get a new power tranny when it bites the dust.
I am repairing one now with that trouble. Tranny's are made with wire coated
with melted plastic, and runs off hot wires. I have some old tranny'a with
enamel coating still working after 70 years. I doubt any of the modern ones
will last very long. The set was designed with a certain power o/p in mind.
To exceed this is looking for trouble
Jack
J M Noeding
<vk4n...@ozemail.com.au> wrote:
>When my FT101E was last checked the power output on the various bands was as
>follows:
>
>160 125 Watts
>80 190 Watts
>40 170 Watts
>20 150 Watts
>15 125 Watts
>10A 100 Watts
>10B 100 Watts
>10C 80 Watts
>
>Perhaps you can get more power with new tubes but you would not notice any
>difference at the receiving.
>
>Best of luck in obtaining Toshiba 6JS6 tubes for the final, they would be
>very hard to locate and of course expensive.
this is considerable better that the FT-901 or FT-902 using 2x 6146B's
(according to my handbook and according to my measurements), so 6JS6
seems to be a much better tube
on 80m I get hardly more than 120W with FT-902, and lower than 100W on
all other bands
While 6JS6 may last 20 years with careful operation, 6146 will sicken
long before this, heard about an owner of Galaxy V mk2 transceiver who
still used the original 6HF5 tubes and they were still at least 90%
good
73
Jan-Martin
--
remove ,xnd to reply
Scott Dorsey
>>
>And remember to find where to get a new power tranny when it bites the dust.
>I am repairing one now with that trouble. Tranny's are made with wire coated
>with melted plastic, and runs off hot wires. I have some old tranny'a with
>enamel coating still working after 70 years. I doubt any of the modern ones
>will last very long.
The older transformers used to be derated a lot more than modern ones, but
the modern plastics are a lot longer lived than the old varnish-dipped
stuff. Unfortunately, it means that manufacturers can now overrate their
products because they can run hotter without damage.
There are a lot of crappy modern transformers out there, but good quality
modern stuff will outlast the good quality stuff of 50 years ago.
>The set was designed with a certain power o/p in mind.
>To exceed this is looking for trouble
The set was designed to be inexpensive disposable gear with cheap sweep
tube outputs. It was not intended to last like high grade military stuff
is, and was built with cheap components. If you run it at the rated power,
you are looking for trouble as it is.
Ron
range in a mag called Ham Radio Today (now defunct) years ago .
His main statement on the FT101 is that the biggest cause of the power
supply and or the tube s to go is capaictor C13 from the 12by7a anode to the
screen grids. Its 80pF at 1KV. its not up to the job . he suggest replacing
with a 80pF or 100 pF rated at 6KV.
Also the cap c131 1000pf at 1KV replace with 1000pF at about 6kv cos that
also causes similar trouble. I think from memory that c131 is switched in
on 160m and or 80m only.
He suggests that befor ereplacimg tube s check that this cap is not faulty
cos if you put in brand new valves thate power suply will go and leave you
with a irg that is useless , unless you make an exterb nal supply.
G3LLL also had a double balanced mixer board (made the rx superb) and an rf
clipper (for those rigs without Specch processor)
I hope this is of help
Ron G4XOU bof...@ntlworld.com
"Grey Fox" <par...@sympatico.ca> wrote in message
news:B8C3F692.2BD8%par...@sympatico.ca...