Re: Electrolytics - FT-101B

#460

My ft101b functioned for about 5 minutes when I first bought it. On my first attempt to transmit with it the PA system gave up the ghost almost immediately.? Turned out the rectifier board had several charred components, and the 12 v side of the power supply had a dead power transistor.??

After repairing the problems with the power supply over the course of about a month, it has produced RF only since this morning. There seems to be more wrong with it than the burned circuit board shown in my QRZ? query.? Fortunately this radio was bought as a tool to teach me tube tech operation and troubleshooting. Looks like it will be good for that!

Show quoted text

On Fri, May 17, 2024, 7:46 PM Pat Carter, N4IU via <patricia=rhinosys.com@groups.io> wrote:

Dan,

I'm not sure what it will need when I'm finished with the recap.? So far when I test, I'm hearing stations where they are spotted, and when I call CQ I'm spotted on frequency.? I haven't taken it above 10W output. It actually has been a fun project.? Do you put your FT101E on the air often?

Pat?

Re: Electrolytics - FT-101B

#459

Dan,

I'm not sure what it will need when I'm finished with the recap.? So far when I test, I'm hearing stations where they are spotted, and when I call CQ I'm spotted on frequency.? I haven't taken it above 10W output. It actually has been a fun project.? Do you put your FT101E on the air often?

Pat?

Re: Electrolytics - FT-101B

#458

Pat,?

I checked on eBay where I bought my recap kit for the FT-101E, but it doesn't show the reference designators.? The E version doesn't have C142, C143 otherwise I would open mind up and see.? Going to be fun.? I see the board change list in the service manual depending on unit serial number will come in handy.? For the chassis I didn't see any change list.??

I'm curious thinking that calibration may be needed after cap replacement.? Are you thinking that too?

Dan
--
73, KK7JNR

Re: Electrolytics - FT-101B

#457

Tom, not sure my answer posted.? I found T12 on the schematic. I can't find any documentation showing that T12 is supposed to have an electrolytic cap? between its leads.? Wondering if your T-12 has this cap. Thanks.

Re: Electrolytics - FT-101B

#456

My version of the service manual lists T12 on the main board (. Highly recommended.) .? It is an AF choke, 20mH, 0.5 A.? I have not found it on the schematic, but have not gone over the entire 24 pages looking for it yet.? Too bad the PDF isn't searchable.? Good luck with the continuing labors!

TH

Show quoted text

On Fri, May 17, 2024 at 1:58?PM Pat Carter, N4IU via <patricia=rhinosys.com@groups.io> wrote:

Tom, thanks for looking. I'm about ready to chalk it up to an undocumented change.? I found another anomaly while working on the chassis.? There is a large transfomer on the bottom of the unit that has "T-12" printed on it.? My radio has a 10 uF electrolytic going between the leads on this guy.? No mention of that part anywhere that I can find.? Does your FT-101B have this part?? I had an extra 10 uF so went ahead and replaced it.?

As to the challenge, it was certainly a mixed bag. I would not have attempted it without a desoldering tool.? I tested the radio after every board or two.? Most of the boards were straightforward. Getting at the caps on PB-1180 (the one in the metal box) was a challenge; and the caps hiding under, and sharing solder joints with, wires and other components on the chassis took some thought.? ?The next project is the big filter caps? I haven't come across any description how to best change these out.? A project for sure.? Good luck with your radio!

Re: Electrolytics - FT-101B

#455

Dan, thank you for searching.? The caps are 1uF and 100uF.? I also have replacements for the C78 and C77 caps in your picture but that is a separate project.

I did buy a kit and there were extra caps for other units.? These are the only two that are listed in the Ft101B manual that I have not been able to find and replace.

Re: Electrolytics - FT-101B

#454

Tom, thanks for looking. I'm about ready to chalk it up to an undocumented change.? I found another anomaly while working on the chassis.? There is a large transfomer on the bottom of the unit that has "T-12" printed on it.? My radio has a 10 uF electrolytic going between the leads on this guy.? No mention of that part anywhere that I can find.? Does your FT-101B have this part?? I had an extra 10 uF so went ahead and replaced it.?

As to the challenge, it was certainly a mixed bag. I would not have attempted it without a desoldering tool.? I tested the radio after every board or two.? Most of the boards were straightforward. Getting at the caps on PB-1180 (the one in the metal box) was a challenge; and the caps hiding under, and sharing solder joints with, wires and other components on the chassis took some thought.? ?The next project is the big filter caps? I haven't come across any description how to best change these out.? A project for sure.? Good luck with your radio!

Re: Electrolytics - FT-101B

#453

Hi Pat,

I checked the service manual and schematic for C142, C143 but could not locate these parts.? Can you provide that schematic.? If you already have the two capacitors, do they look like this and are they 100uF, 500V?? If so, maybe they are C77, C78.? Did you buy a capacitor kit or just replacing them one by one on your own.??

Dan
--
73, KK7JNR

Re: Electrolytics - FT-101B

#452

Looked this morning on 2 different documents for your caps and could not find them either. I feel your pain.?? Just now I'm trying to resurrect a 101B purchased in working order (hah!).? I successfully rebuilt the rectifier board and am now trying to see if it puts out a signal.? Searching for 'bad looking' components visually did not turn up any bad caps, but I should go through the entire replacement exercise soon.? Overall did you consider it a challenge? I am new to this and wonder if that might be opening a can of worms...

Electrolytics - FT-101B

#451

Hello, I have been replacing the electrolytic capacitors in my radio, and have gotten down to C142 and C143 listed on the parts list as being on the main chassis.? I can't find them either on the schematic or on the radio.? Does anyone know where they are located?

Re: FR-101D with LED display?

#450

开云体育

Erwin,

?

Thank you so much for the schematic for the PB-1827 LED version. I have one of these LED receivers as well as several of the more common VFD versions and have never been able to find any documentation for the later LED version. I don’t think Yaesu made many of these before production? ended.

?

Tom / W7OA

?

Show quoted text

From: Yaesu-FT-101@groups.io <Yaesu-FT-101@groups.io> On Behalf Of PA3DAF
Sent: Sunday, May 12, 2024 1:41 PM
To: Yaesu-FT-101@groups.io
Subject: Re: [Yaesu-FT-101] FR-101D with LED display?

?

GOT IT!

I found a "Yaesu FR-101 Digital Counter Unit instruction manual" with discription and partlist of the VFD tubes version BUT with a schematic of the PB-1827 LED version. I uploaded it to the Files section.

Erwin, PA3DAF

Re: FR-101D with LED display?

#449

GOT IT!

I found a "Yaesu FR-101 Digital Counter Unit instruction manual" with discription and partlist of the VFD tubes version BUT with a schematic of the PB-1827 LED version. I uploaded it to the Files section.

Erwin, PA3DAF

Re: No SSB Tx - Help!

#448

Hello again to the Group.
I have swapped out the PB-1534 from the working unit to my faulty one which had no SSB Tx?and have resolved the "No-SSB" problem.?So if ever you have no SSB drive (or SSB power output) then you can look carefully at this board.
I will now verify the defective board. Likely a change of the FET's will bring it back to life.
Once diagnosed and repaired, I will advise on my findings.
Regards to you all.?

73 de

Claude - VE2YI

ceverton2222@...

No SSB Tx - Help!

#447

Hello to the Group. Any help would be greatly appreciated.

I have a friend's 2 FT-101E's here and both had essentially the same operational problems, that is both worked well on all modes, Rx & Tx on AM and CW, but no SSB Tx.?

I did get the first one going by cleaning both Relay #1 and the Mode switch. The 2nd runs well both on Rx and TX on AM and CW, but also no SSB TX.

Looking at the Tx signal on my Spectrum Analyser in SSB mode, I can see a minimal carrier (-110dBm or so) and whistling or talking into the mic the signal rises perhaps 10dB or so, but the audio I hear is AM not garbled (not SSB) and no power to speak of. I've gone through this rig pretty rigorously and found several minor problems,? out of tolerance resistors, leaky caps, and Q6 on the PB-1534 which caused a No ALC issue but having replaced it with a similar FET I do now have ALC but still no SSB drive. Bias on the Finals and driver are good (60mA and 20mA), so I'm in at a loss and becoming frustrated. I also swapped out all of the boards and both relays from the working unit to this one and I have the same problem, so it's got to be something that I haven't swapped out, the PB-1534 or the mode switch? Anyone have any idea on what I'm missing here?

Thanks for any assistance.

?

73 de

Claude - VE2YI

ceverton2222@...?

Re: ft101b HELP with power supply removal

#446

Thanks for your reply, Emerson.? I have the board out and am currently removing and testing components.? Surprisingly the badly charred resistors test right on the money.? Some of the smaller components outside the charred area are dead as doornails.? Go figure.? I will replace everything with obvious damage or that tests as marginal. We'll see how it goes!

73,

Tom. KO4HNB

Re: ft101b HELP with power supply removal

#445

Tom

It is possible to remove it. It's not easy but I did that.? Probably it is necessary to verify all components.

take a picture and note the position of all the wires

You can loosen the screws on the other side where the plate is fixed. To do this, you have to remove the speaker to access the screws on the support.

Now if I remember correctly these burned resistors belong to the inverter circuit. In other words, the ft101 can work without them.

good luck

Emerson

PP6EW

?

Em seg., 25 de mar. de 2024 às 00:17, Tom KO4HNB <alnath14308@...> escreveu:

Show quoted text

All-
I bought a cheap Yaesu ft101b to learn about tube HF.? Based on guidance from this board I started it on a dim bulb tester (receive worked), tuned it per manual and service manual (they do not agree, but both tuned it).? Set it for 1/2 power and transmitted into a known resonant 20m dipole.? Got about 60w out. Groovy!? Next day it only received!!!?? Stopped and pulled the case to look for c13 and c125 to replace them if still the originals per instructions here and elsewhere. I found sources saying? this is what happens if C13 fails open.If it fails shorted, fire ensues.? I have had no fire, smoke, or evil smells from the 101.

Opeed case and found this inside (see photos of rectifier board PB1076B.)

This is PB1076B, the rectifier board.? That stuff is not spray on insulation, the components are partially carbonized. And it still receives.? Tough radio.

How do you remove this board?? It appears to have been born in this position and cannot be removed without explosives. Most everything else looks accessible, but not this.? No other damage evident anywhere.

How can I get this board out? Anyone have one to sell? And while I'm asking, where are the C13 and C125's I need to replace?? I have found several with those numbers.

Thanks for any help available.? I think I made or bought a mess.

73,

Tom
KO4HNB

ft101b HELP with power supply removal

#444

All-
I bought a cheap Yaesu ft101b to learn about tube HF.? Based on guidance from this board I started it on a dim bulb tester (receive worked), tuned it per manual and service manual (they do not agree, but both tuned it).? Set it for 1/2 power and transmitted into a known resonant 20m dipole.? Got about 60w out. Groovy!? Next day it only received!!!?? Stopped and pulled the case to look for c13 and c125 to replace them if still the originals per instructions here and elsewhere. I found sources saying? this is what happens if C13 fails open.If it fails shorted, fire ensues.? I have had no fire, smoke, or evil smells from the 101.

Opeed case and found this inside (see photos of rectifier board PB1076B.)

This is PB1076B, the rectifier board.? That stuff is not spray on insulation, the components are partially carbonized. And it still receives.? Tough radio.

How do you remove this board?? It appears to have been born in this position and cannot be removed without explosives. Most everything else looks accessible, but not this.? No other damage evident anywhere.

How can I get this board out? Anyone have one to sell? And while I'm asking, where are the C13 and C125's I need to replace?? I have found several with those numbers.

Thanks for any help available.? I think I made or bought a mess.

73,

Tom
KO4HNB

Re: FT-101 EE PB1547 Voltages

#443

I replaced the Q3 2SC784, and the B-C-E voltages test good now, so we’re making progress. However still no TX output. After tuning against dummy load, and then connecting to MFJ-904 tuner and antenna, the meter (set on P.O.) shows zero when switched to MOX, but jumps to S7 momentarily, instantly after switch is snapped back to PTT, then slowly settles back to zero.

Vince, KN6KKZ

Re: FT-101 EE PB1547 Voltages

#442

Emerson,?

Thank you for sharing that BF199 interchange information. I’ll definitely make note of that for future reference. I was able to locate a pair of new original Toshiba 2SC784 that just arrived today. I am anxious to replace it this weekend and see what happens!
Thank you again,

Vince, KN6KKZ?

Re: FT-101 EE PB1547 Voltages

#441

Vince

I? have replaced Q3 2sc784 by a BF199.

Emerson

PP6EW

Em sex., 8 de mar. de 2024 às 11:20, Vincent Fischer <vf6fhellcat@...> escreveu:

Show quoted text

Emerson!
Have you led me literally STRAIGHT to the likely source of my TX issue?! Please check out the Q3 transistor base voltages in attached image.
Thank you,
Vince, KN6KKZ