开云体育

Thanks Mat,
I do hear ANT and marker CW and SSB signals coming from the AF VCA on the back which I feed into an external amplifier(I can hear why FT-980 is highly regarded!)?

I do hear pops in the external speaker, internal speaker, and headphones on power up.

With marker signal ON and in CW mode
The APF button does change the levels when pushed.
I've confirmed signals on the AF unit on? J07 pin (1) AF IN, pin(6) APF out, pin(7) AF VR
J08 pin (1) AF out

and NO signal J11 pin(1)AF IN , J07 pin(3) SIDE TONE on the?AF unit?
---------------------------------------------------------------------------------------------------------

then I checked around the Monitor unit? schmatic ref(M)?which then goes thru R2302(2.2K) to J04 pin(6)AF IN .....and therefore nothing on pin(4) AF OUT
?
But this is where I can't find it any more???? is R2302(2.2K) a in line or on the APF SWITCH board (which is hard to see)?
because I get signal from the pin(7) AF VR signal and from ?pin(6) APF out and see the insertion loss when I press APF......
I suspect R2302(2.2K)?????
if so where is that resistor???? That circuit board is super hard to get at and the audio coax seems to move somewhere else in different direction.
I tried a conductivity test but could find anything yet..getting somewhat frustrated...but can't give in now!


BTW I've confirmed good power and gnd on the AF Unit uPC20002V audio amp...but no input signal of course and therefore no SP out


Can anyone follow me or should I check anywhere else?

Much appreciated !!!!!
73, David VE3DPC?

As another possible debug method, are you able to plug an external speaker into the "EXT SPKR" jack on the back:

1. This could eliminate the possibility of a bad on-board speaker?
2. The jack actually acts as a switch to disable the on-board speaker (when an external speaker is plugged in). If the jack-switch is bad, it would match some of the symptoms.

Note: If the headphone jack is bad, it too might result in the internal speaker being disabled. I'm not convinced either of these is true (because you hear an initial pop), but might be worth trying to eliminate.

Have you turned the APF on/off? Note the different paths below.?



Just some thoughts ...


--
-Mat Breton, N8TW

Thanks Mat and all you guys much appreciated .... I don't know how to repay ...but first I shall keep probing.
I've got the unit filleted on my bench and found the audio( using the 25Khz harmonic "Marker" which I hear on CW) in around the AF UNIT ...so I think it leaves to monitor board ...the Marker signal gets converted to the side-tone which is I hope fine for signal tracing.
I 'm stuck in there between Monitor Pot and where it returns...I've down loaded a few schematics and board layouts from this groups.io FT-980- Technical manual?
73,
David VE3DPC

FYI: There are better versions of the manuals (including technical) in the files section of this group. Improved scans, OCR, etc ... thanks to good work from our members.


--
-Mat Breton, N8TW

Hi Dave,

Sorry I wrote "cinch" , but you are right for RCA jack ! ..a small difference between Europe and American contient !

To fix your FT890 you sholud print the schematic of the "technical supplement" (service manual). You can find on the net ()

AF out is comming from AF unit, but the signal goes to Monitor unit, then to AF volume knob, then to audio amplifier on AF unit again ! ...then to rear speaker jack, and finally to speaker
With printed schematic and a oscilloscope you can fix it !

good luck :-)
73 JMat F5RCT

On Tue, Jan 18, 2022 at 10:18 AM, <f5rct.jm@...> wrote:

AF out

Hey JMat...thanks for suggesting that ........It's alive !!!
from the AF RCA jack out the back....beautiful 20m cw music.

Not sure why you said "Cinch" as the audio is appearing from the RCA jack...maybe ACC-1 as well?

So trace back into AF unit?
Where to start .....at the entrance to the Audio board PB-2375A (or SA)

I'm going in...
73, David VE3DPC

HI Dave,

The P98 connector is used for keyer option when equiped. This connector has nothing to do with your problem.
(The KEYER knob goes to this connector to adjust the speed.)
I suggest to start your investigations from AF unit... You can check AF on rear panel at "AF out" Cinch, this output is before AF amplifier.
73, JMat F5RCT

On Tue, Jan 18, 2022 at 08:01 AM, Fred_N8YX wrote:

Can you receive anything in AM or FM modes?

Hi Fred..thanks for helping..
NO AM or FM is heard.
I do see the s-meter pulsing back a forth a bit...and I adjusted the SQL knob for FM but no audio heard.

I found out the P98 connector is for a keyer option which I guess was not installed...should affect anything accept make me a better Straight Key op!

Is it something basic I do not have set right? I followed page 23 in FT-980 operation manual for initial settings.

Should I remove bottom and back cage and check some connections?
73, David VE3DPC

Bumping this one again...

Tuning problem resurfaced yesterday. Looks like I'll be soldering ICs. Will update the group as soon as the covers are back on the rig and it has some run-time. Hopefully the 14093 fixes things else I'll be diving further into the Dial Units - and after that the CPU Unit.

73 - Fred, N8YX

I second Wald's observation regarding the handle. I was toting my spare '980 to storage - rather, attempting to - when one of the screws in the handle let go. Fortunately, it was only a few inch drop onto a carpeted floor...

ATT knob: A number of Yaesu rigs of the period used cosmetically similar ones. If Wald's source fails to deliver, the auction site usually has at least one set off something which contains the correct knob.

Screws: Look at M3 computer screws in black finish; 6 or 8MM length. These will be a perfect match for the originals. (Now if I could only find them in Winter Gray, to match those used for the FT-901/902 covers.)

73 - Fred, N8YX

David,

Can you receive anything in AM or FM modes?

Wald, as far as the snowstorm goes...16" here in NEOH and we're still digging out, plus fighting the city to get plow trucks onto the hilly side streets. These haven't been touched since it started Sunday night.

73 - Fred, N8YX

On Tue, Jan 18, 2022 at 06:28 AM, Wald N4PL wrote:

Hi again Wald.....OH Georgia is always on my Mind!!!

Have a travel thru a few times ..clay on my tires .... we got 2 feet of snow into central Ontario and we were stuck.

When you key up the TX, can you hear the side tone? yes I hear a beautiful tone and tried all 3 side tones 700 etc Moni knob working good..

I plugged in 1/8" ext speaker and headphones and sprayed a touch of DeOxit in there too

es the ext speaker and headphones produce side-tones.

I tried the AF KNOB rotating it and can very faint sounds in the main speaker....but just like low level pot noise

Is this correct ? is the right analog meter functions as a? ALC/SWR/S-meter??
When I TX the meter moves to left indicating "low" SWR...which is good I think
But I'm confused why when i turn the input RF gain knob CW the S-meter moves lower I would have thought the other way around??


**I also noticed a a P98 plug that is just hanging out not plugged into anything???*
its near the front panel and there is standoff from bottom PCB that has nothing secured to it?
Perhaps the previous owner (SK) had a filter board in there and removed it but are jumpers or something...I'm investigating but is that barking up wrong tree?

? 73, David VE3DPC

Thank you for the welcome Wald,
especially from work.....I'm working from home due to snow storm....so I was able to try the marker square generator?

I report no audio thru speaker but do notice the ALC meter (set to SWR) jumps at approx 25Khz spacing

Why would that be? I thought ALC was for TX monitoring??

Also I when tried a straight key on CW (i've got my ext ant tuner connected) the SWR meter on TX goes down to 1.1
even I have the RF "drive" knob turned to zero
Previously I did TX with some "drive" and saw my PO meter on tuner move..so I think I have a Transmitter.

I have an RF probe and Oscilloscope handy...es started to study signal path...have to build the probe 1st?

73, David VE3DPC

Hi all 1st of all thanks for any support you may give to get this beautiful radio to RX...it does TX on CW at least haven't tried SSB

1.started by putting fresh 2x AA batteries in the memory backup...they were not installed so no corrosion issues.?
2. I reviewed the Basic operation manual for initial settings and confirmed the power up sequence ...goes to GEN 7.000 I hear a speaker pop telling me its getting a DC level at PWR up.
Turned up the AF control and nothing not a peep!
NOTE: being a skeptic i wonder could the external RX ANT switch be faulty?? so
should I contact(DeoxIT) clean it?
3.tried the BFO CVC cap adjustment ....set to 6V USB IF shift set CCW ; but when I went to LSB the DC meter only goes to 5V not down to 3-4 VDC the manual says when I move the IF shift CW

next steps check the TX/RX relay?......where is it? in the back cage I imagine.
or something else could be the problem?

Did DR. Jose Carlos find his RX issue??

73
David
VE3DPC

I had not even noticed the ATT knob, if he has the original can you ask him if he would be willing to sell it, I am looking for the top and bottom metalwork as well. also the handle, I think just for completeness I will try and fit the handle, I have noted your thoughts on it, but would like finish the look, going to open her up tomorrow.

I finally got around to un-earthing the radio, still nit applied power to it yet, just put on the bench to take a look at it.

It’s certainly had a hard life.

Missing the handle and quite a few screws showing tell-tale signs of being removed a lit more than just once.

And even totally wrong looking screws in places.

The rear view is about the best angle.?

So are there any pointers as to the best place besides ebay to find parts, certainly need a handle and im sure that the other side should have feet which are missing, plus may be on the hunt for some cleaner metalwork.