Ok. ?If I not could explane quite well. So, measurements/stetps from connections are same on VFO and? CPU torstai 28. tammikuuta 2021 Mat Breton < i.m.n8tw@...> kirjoitti:
When I get time I'll dig into the schematics again. We are missing something I think ...
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-Mat Breton, N8TW
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When I get time I'll dig into the schematics again. We are missing something I think ...
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-Mat Breton, N8TW
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Sorry! Measuring the voltage changes when spin the VFO dial, steps? J01(P06) From pin C164, C165 ... 1khz, 2khz, 4khz, 8khz, 10khz, 40khz, 60khz, 80khz, 100khz. Same lsb and usb on 3.7Mhz. No hz changes, only khz in frequency.
When measuring from CPU board connection, so I have to check those measurements above. Because, steps Pin 1ok. Pin 2, 2 khz or 4 khz,? Pin 3, 4 khz or 6 khz and? Pin 4, 8 khz or 2 (two) khz?
This time I spin the VFO dial hundreds of khz at the same direction.? I repeated measurements severel times, because thought the error of the multimeter. Don't know if I made a new fault. Aimo, OH6NES
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All,
If I was a betting man (and I've been known to wager a bit here and there) I'd place money on the problem being with Q27, a uPD8255AC-5 programmable I/O controller. This takes muxed CPU data and drives a number of subassemblies in the rig, among them the VFO and PLL.
One of these ICs went bad in an FT-980 and caused the tuning to simply not work (among other problems). Replacing it fixed the issue. Yaesu must have foreseen potential troubles in this portion of the CPU Unit, as Q25-Q27 are socketed.
73 - Fred, N8YX
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Very good, we are making progress I think. It appears that the CPU commands are not reaching the VFO PLL. Since the CPU separately drives the VFD display, this would explain all the symptoms you are seeing. We have a good idea of what the problem is ... we just need to locate where the problem is :)
Note: I say "appear" because there is a small possibility the decoder/counter IC on the VFO board is fried and holding the lines up/down. More on that below ...
Next is to check the interconnects: the FT-980 VFO PCB (like most of Yeasu's PCBs in that era) is a single-sided design. These types of boards have known long-term reliability issues with solder joints due to the uneven flexing that occurs as they heat & cool. Additionally, the boards are neither temperature-stabilized nor fibre-reinforced, which exacerbates the issue.
Going to the CPU board, can you check the equivalent pins on that side (J6003 & J6013 I believe):
Outcome 1: If you see the correct signals there, we know we have an interconnect problem.
Outcome 2: If you don't see the signals, we need to eliminate the possibility of a fried VFO IC: disconnect the bus between the boards and retest. I
Outcome 2A: f we have a bad VFO IC the signals should "magically" start working.
Outcome 2B: If they do not, it would appear to point point to a CPU board issue. We'll cross that bridge if it comes to that.
Give these next set of tests a try and we should hopefully figure out where the issue is!
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-Mat Breton, N8TWn
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Measuring the voltage changes when spin the VFO dial, steps? J01(P06) From pin C164, C165 ... 1khz, 2khz, 4khz, 8khz, 10khz, 40khz, 60khz, 80khz, 100khz. Same lsb and usb on 3.7Mhz. No hz changes, only khz in frequency.
tiistai 26. tammikuuta 2021 Mat Breton < i.m.n8tw@...> kirjoitti:
OK, I have an idea. But first a few basics:
1. The VFO frequency is driven by a microcontroller controlled PLL into the 1st mixer. The scheme is pretty complex and is shown on page 49 of the tech supplement.?
2. The Microcontroller controls this PLL via a 21-bit wide digital bus.
We don't know if the problem is in the PLL or the microcontroller (or the connectors/wiring between), so let's first divide the problem in two.
Using a multimeter, check the VFO board connectos P07 and P08. P07-Pin 1 is the LSB, and P08-Pin13 is the MSB. As you spin the VFO dial, you should see the lower level pins toggle back and forth in BCD-like fashion (pin 1 toggles every 10 hz, pin 2 toggles every 20hz, pin 3 toggles every 40 hz, and so on).
Give this a try and let us know if the uC signals are getting from the CPU board to the VFO board!!!
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-Mat Breton, N8TW
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OK, I have an idea. But first a few basics:
1. The VFO frequency is driven by a microcontroller controlled PLL into the 1st mixer. The scheme is pretty complex and is shown on page 49 of the tech supplement.?
2. The Microcontroller controls this PLL via a 21-bit wide digital bus.
We don't know if the problem is in the PLL or the microcontroller (or the connectors/wiring between), so let's first divide the problem in two.
Using a multimeter, check the VFO board connectos P07 and P08. P07-Pin 1 is the LSB, and P08-Pin13 is the MSB. As you spin the VFO dial, you should see the lower level pins toggle back and forth in BCD-like fashion (pin 1 toggles every 10 hz, pin 2 toggles every 20hz, pin 3 toggles every 40 hz, and so on).
Give this a try and let us know if the uC signals are getting from the CPU board to the VFO board!!!
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-Mat Breton, N8TW
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Tnx for reply.
No others, only those two.
Btw. I have Ft-980 Technical Supplement and I have measured values on the vco/pll and vfo units. BUT.
Don't know where to start. In how many places the frequence is regulated and expecially those hz/ 10 hz steps.
What to check and in what order.
Changin components, etc.
73
Aimo, OH6NES
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Hi Aimo,
Nothing comes to mind (LDB shouldn't cause this for example). I haven't seen this on my rig ...
Q: Are there any other LEDs lit except
? ? ?1. VFO (above the display)
? ? ?2. Ham (above the Ham button)
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-Mat Breton, N8TW
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Hello, in my FT-980:? when rotating vfo knop, in the display numbers are changin by 10 hz,thats ok, but the real frequency is not changin until one khz is reached. So, by one khz steps. I have replaced some parts in vfo board, no success.
I appreciate, if someone can give me advice, where to start , "march order".
73's Aimo, oh6nes
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Fred,
Most 980 users looked at the Yaesu and Yaesu pulled that mod.? Not sure what K4DPK did but it caused problems on CW and FSK TX.? He is a SSB guy. Not sure of the later mod as the GEN TX I want is limited to 60 meters. Dave
-----Original Message-----
From: Fred_N8YX
Sent: Jan 20, 2021 12:53 PM
To: [email protected]
Subject: Re: [Yaesu-FT-980] Files Update
Dave,
Which "Yaesu Gen TX Mod" are you referring to - the one they published early on, or the kit they offered (which included a buffer board)?
What is the caution against using either?
73 - Fred, N8YX
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Re: Is this a factory mod?
I currently have four FT-980s plus about half of another in parts. It's my favorite rig, and I've owned a LOT of various models of gear over the years.
The solution to the linear problem comes in the form of an FL-7000. I have one station thusly configured and another '7000 awaiting installation when I redo my shack.
73 - Fred, N8YX
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Dave,
Which "Yaesu Gen TX Mod" are you referring to - the one they published early on, or the kit they offered (which included a buffer board)?
What is the caution against using either?
73 - Fred, N8YX
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Re: Is this a factory mod?
Mat,
Maybe only for USA I know many were sold in JA for their 10 watt rig.? K7JA then at Yaesu sent me the 10 amp board which I used once and sent back replacing it with my 100 amp board.? I also know many were sold in the UK as this is were a lot of boards on EBAY come from. 73 Dave K4JRB
-----Original Message-----
From: Mat Breton
Sent: Jan 19, 2021 8:54 PM
To: [email protected]
Subject: Re: [Yaesu-FT-980] Is this a factory mod?
I've seen two other FT-980 for sale in person: one was at Dayton, and another at Findlay.
Only 600 made (I assume for US market)? I maybe should have bought another one!?
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-Mat Breton, N8TW
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Re: Is this a factory mod?
I've seen two other FT-980 for sale in person: one was at Dayton, and another at Findlay.
Only 600 made (I assume for US market)? I maybe should have bought another one!?
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-Mat Breton, N8TW
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I tried the ft-980 io group and my group came up without the need to sign in.? I clicked on the files and got them all.?
Here are a few things about the FT-980 a user needs to be aware of... 1.? Early 980's had a problem with QSK and that is why the FRB-1 relay box was produced by yaesu at the urging of Carlos TI2CF. 2.? The little relay that switched between GEN and HAM can get dust inside the cover that needs to be cleaned out from time to time. 3.? The best was to operate split was to set up split bands in memory just wish there were enough memories to set sp0lit bands for SSB and CW. 4.? The 980 should sound the same between upper and lower sideband and if not the little capacitor in the vcv circuit needs to set to correct.? You need to use an alignment tool to do so.? I replaced the capacitor in my original FT-980 with a better capacitor as the original would break. 5.? Do not use the Yaesu GEN TX mod.? K4DPK had a better mod but it is lost in time. 6.? A 1985 DOS program to actually CAT the transceiver was good but the windows version was in progress when the author lost his hard drive and the windows version was lost. 7. The original apple interface was replaced with the FIF-232C by Yaesu but I found it clumsy and Ham Radio Deluxe? program said the transceiver was too old to support.?
8. Some amps were hard to support even with the relay mod suggested by Yaesu so use the FRB-1 relay box to assure proper relay control. 9. The Curtis keyer never did let me set spacing's even usin a nice Vibroplex paddle. I found an outboard keyer was a better solution.? N4PL built a kit keyer to put in place of the curtis works great and even cured the first character truncation that N5IA found while operating the CQ 160 CW contest. ? ?
This all of the problems I ran into over time.? Recently I found problems with wobble in the main tuning dial and problems in the main mode switch that stopped CW and FSK to go out.? For some reason SSB and AM always worked.? You need FSK to tune up a linear.? Many boards can be found on EBAY to replace boards on your FT-980 that go bad and at a reasonable price to save you tracking down the bad parts.? Most I have seen are reasonable prices. I got a new CPU board that worked great but beware the board is at the bottom of a stack of boards boards so use caution or screws with drop into the stack.
73 Dave K4JRB
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Re: Is this a factory mod?
Thanks Roger and Wald.? My original FT-980 was purchased in 1983.? I bought a used 980 from K4DPK who modified it for GEN TX which I used the memories for those 60 meter channels.? My next two were given me by the family of a silent key.? THe one with a relay added is with Wald N4PL.
Back in the early 1990's there was a group of 980 users and I copied the pages of the FOX Tango newsletter with? 980 improvements.? I made 15 copies and last year I only had 2 copies left.? Chip K7JA and I talked at Dayton 1n 1994 and he told me the 980 had the best receiver they ever made (he was VP of Yaesu USA.? Good to see the ole gal now has a reflector.? They made about 600 of the FT-980.?
73 Dave K4JRB
-----Original Message-----
From: Roger VE7LB
Sent: Jan 18, 2021 6:46 PM
To: [email protected]
Subject: Re: [Yaesu-FT-980] Is this a factory mod?
Hi Dave,
Go to /g/Yaesu-FT-980 sign in with your groups.io credentials. In the left pane click on the Files section near the bottom.
73
Roger VE7LB
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Re: Is this a factory mod?
Hi Dave, Go to /g/Yaesu-FT-980 sign in with your groups.io credentials. In the left pane click on the Files section near the bottom. 73 Roger VE7LB
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Re: Is this a factory mod?
Roger,
How do I get to the files section? 73 Dave K4JRB
-----Original Message-----
From: Roger VE7LB
Sent: Jan 17, 2021 6:55 PM
To: [email protected]
Subject: Re: [Yaesu-FT-980] Is this a factory mod?
[Edited Message Follows]
Hi Wald,
I did a search of the Fox Tango FT-980 newsletters and found pages 8348, 8349 and 8352 about keying a Heath linear. Does this seem to be the relay mod? If it is the mod it is a Yaesu approved mod that you had to do yourself with parts supplied by Yaesu.
Suggest searching the Newsletter pdf in the files section when you start checking out the other mods.
73
Roger VE7LB
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Re: Is this a factory mod?
I had to do this with my Henry linear, but I used an external relay box (and used a "solid-state" relay to minimize noise/maximize life, switch faster). Unfortunately can attest that if you don't do this, you can possibly damage the master "T/R" relay on the REG board that controls which changes all the circuitry inside the rig between the two signal paths.
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-Mat Breton, N8TW
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Mat Breton N8TW