Re: Assorted '980 ramblings and repairs
Great update Fred!? Thx.
On my end, I wanted to comment about my CW-N filter mod that I posted earlier. I cascaded two CW filters (455 kHz and 8.9 MHz) to get a better selectivity.? That objective was achieved at the expense of additional loss in the IF chain.? It did not initially sound too bad but in a real life, when listening to really weak CW signals - switching from CW-W to CW-N would cause the desired signal to almost disappear.? So I do not recommend this mod anymore.? I will unmodify my radios and remove the 455 kHz filters.? If anyone on this needs one or both, they will be available at my cost ($45 plus shipping).
73, Wald N4PL
On Sunday, December 12, 2021, 04:24:40 PM EST, Fred_N8YX <n8yx@...> wrote:
Figured I'd tickle the list a bit to keep it active.
Pulled one of two FT-980s currently inline out of line in preparation for replacement of TC4001 and all the electrolytics on that particular assembly. The other I'm using for my FT8 position - which works great under computer control but after warmup, the main tuning encoder won't change operating frequency when tuned downward. I have a game plan for both of these.
The third '980 I own - in the queue for some time now - needs some updates (filters, the Gen TX kit installed) and will become a backup to the other two when done. #4 needs its front panel replaced and ultimately will become a guinea pig for other mods I have planned...including deciphering the Aux Band ROM programming.
A TS-930S replaced the first '980. An FL-7000 was connected to the Yaesu and I'll cable the Kenwood up to it as soon as the amp cable I ordered arrives. (Would usually build this stuff but Ye Olde Junque Box is fresh out of 7 pin DIN males.) It's nice to let the rig control the amp for band and tuner changes but I guess I'll live with manual operation for the time being. The '930 was modded pretty extensively a few years ago and I'm pleasantly surprised how well it works on the crowded low bands. Alas, its internal tuner is less than optimal for rapid QSY - which is why an FT-980/FC-757AT replaced it for FT8 duties.
Hopefully, the G0 with a '980 problem (on a QRZ thread) shows up here and we can all assist with keeping another one on the air.
73 all - Fred, N8YX
|
Assorted '980 ramblings and repairs
Figured I'd tickle the list a bit to keep it active.
Pulled one of two FT-980s currently inline out of line in preparation for replacement of TC4001 and all the electrolytics on that particular assembly. The other I'm using for my FT8 position - which works great under computer control but after warmup, the main tuning encoder won't change operating frequency when tuned downward. I have a game plan for both of these.
The third '980 I own - in the queue for some time now - needs some updates (filters, the Gen TX kit installed) and will become a backup to the other two when done. #4 needs its front panel replaced and ultimately will become a guinea pig for other mods I have planned...including deciphering the Aux Band ROM programming.
A TS-930S replaced the first '980. An FL-7000 was connected to the Yaesu and I'll cable the Kenwood up to it as soon as the amp cable I ordered arrives. (Would usually build this stuff but Ye Olde Junque Box is fresh out of 7 pin DIN males.) It's nice to let the rig control the amp for band and tuner changes but I guess I'll live with manual operation for the time being. The '930 was modded pretty extensively a few years ago and I'm pleasantly surprised how well it works on the crowded low bands. Alas, its internal tuner is less than optimal for rapid QSY - which is why an FT-980/FC-757AT replaced it for FT8 duties.
Hopefully, the G0 with a '980 problem (on a QRZ thread) shows up here and we can all assist with keeping another one on the air.
73 all - Fred, N8YX
|
Hi Rocco, indeed the same behaviour applies to my rig: about 90% of mic gain is needed in order to achieve Alc compression. In my case the simple hand microphone is used. Did you discover any news on this topic? Perhaps you're right on asking more gain to this stage.
Regards?
Enrico?
|
Hi Enrico. In fact, the calibration procedure of the AMGC is not at all mentioned.
I thought it might serve the gain of the TX-IF chain.
This is because I tried to use an MD-100 in THRU mode and without a processor I have to keep the micro at 90%.
With the Turner + 3 it goes significantly better.
With the processor inserted, to have the peaks between 5-10 of compression, COMP must also bring it to 90%.
73 IK6GQC? Rocco
|
Hi Jose, When properly set, the IF Shift "function" should not be affected by switching from USB to LSB and back. The audio passband should not "change" by shifting the SSB mode. Note: you can "observe" the passband by running the audio into an PC-based FFT program like Spectran, while making sure the AGC is off. I tried tried to describe the shift function in the repair article " Wireless Article - FT-980 BFO-Shift Oscillator Fix - Part 1.docx?".?It is quite ingenious how they apply the oscillator twice, one each side of the 3rd IF, to ensure that errors and drift cancel each other and don't affect the passband. You can also see how i used the PC-FFT software to "watch" the passband as I used the IF-width and IF-shift knobs, and switched mode, to ensure that this stage was functioning properly. Hope this helps! -- -Mat Breton, N8TW
|
Hi Rocco, you are right: no explanation in Tech Supplement about VR09 in IF Unit. I think it is used to set the polarization of Q36/JFET working as AMGC Gate.
Indeed I didn't care of it when I retuned the rig because I don'use AMGC and the rig is properly working with AMGC off. Perhaps the IF UNIT VOLTAGE CHART, where Q36 is listed both for AMGC ON and OFF, may be helpful.?
Let me know if you have any news about it.?
Best regards
Enrico IK2XEI
|
Wich is the function of VR09 on the IF UNIT near Q34-35-36 ?
On which page of Technical Supplement can you find the adjustment procedure?
Thank's to all
73 IK6GQC? Rocco
|
|
|
Mat,
should you return the IF SHIFT control when go from USB to LSB and viceversa?
Dr. José Carlos León Ortega UDI- Universidad para el Desarrollo y la Innovación Tel. (591 3) 3422525
Santa Cruz - Bolivia
On Friday, October 8, 2021, 02:05:41 PM GMT-4, Mat Breton N8TW <i.m.n8tw@...> wrote:
My BFO likewise tunes similarly: max to 6V, but min is only 5.something (I forget) volts. Works fine. This is even after replacing the original trim-capacitor with a much better one.
--
-Mat Breton, N8TW
|
|
|
Very thanks Enrico for your reply.
Really radio works on USB and LSB, but I always should to move the IF SHIFT control for best tuning. It is a testimony that something is not ok on CVC circuit. If I am listening on USB and switch to LSB, I should to retuning the IF SHIFT control and viceversa.?
Best regards. CP6CL
Dr. José Carlos León Ortega UDI- Universidad para el Desarrollo y la Innovación Tel. (591 3) 3422525
Santa Cruz - Bolivia
On Friday, October 8, 2021, 11:48:11 AM GMT-4, <e.tallone@...> wrote:
Hi Jose, I made the same experience some months ago, when I retuned the whole rig. I don't remember the precise values but I remember a similar behaviour.
Nevertheless no problem at all arose from CVC despite the discrepancy resulting from Tec Supplement: the frequency range covered by CVC is wide indeed, and the result was that the CVC PLL turned always in lock for USB (ful ccw or cw) and LSB (full ccw or cw) settings. This may be quickly checked on the rig with a counter reading the CVC signal frequency varying the USB/LSB/ccw/cw settings.
I also noticed that the equipment with low serial numbers (the first production lots) were modified by Yaesu in the CVC: perhaps the Tec Supplement refers to the previous HW version?
At the end of the day, despite what is declared in Tec Supplement, the main goal is that the CVC PLL will be able to lock with a Vtune value high enough to preserve good phase noise characteristics from CVC. The final check on frequency value, varying USB/LSB and full ccw/full cw, will dispel any doubt on the correct behaviour of this RX part.
I had various problems with my FT980, mainly due to internal coax connections/pcb tracks/electrolytic capacitors. I spent many hour on it but I'm now proud owner of a fully efficient regal rig.
Best regards
Enrico IK2XEI
?
|
My BFO likewise tunes similarly: max to 6V, but min is only 5.something (I forget) volts. Works fine. This is even after replacing the original trim-capacitor with a much better one.
--
-Mat Breton, N8TW
|
Hi Jose, I made the same experience some months ago, when I retuned the whole rig. I don't remember the precise values but I remember a similar behaviour.
Nevertheless no problem at all arose from CVC despite the discrepancy resulting from Tec Supplement: the frequency range covered by CVC is wide indeed, and the result was that the CVC PLL turned always in lock for USB (ful ccw or cw) and LSB (full ccw or cw) settings. This may be quickly checked on the rig with a counter reading the CVC signal frequency varying the USB/LSB/ccw/cw settings.
I also noticed that the equipment with low serial numbers (the first production lots) were modified by Yaesu in the CVC: perhaps the Tec Supplement refers to the previous HW version?
At the end of the day, despite what is declared in Tec Supplement, the main goal is that the CVC PLL will be able to lock with a Vtune value high enough to preserve good phase noise characteristics from CVC. The final check on frequency value, varying USB/LSB and full ccw/full cw, will dispel any doubt on the correct behaviour of this RX part.
I had various problems with my FT980, mainly due to internal coax connections/pcb tracks/electrolytic capacitors. I spent many hour on it but I'm now proud owner of a fully efficient regal rig.
Best regards
Enrico IK2XEI
?
|
Hi, friends,
I tried to do the aligment described on pag 23 of Tec Supplement. BUT, I have not succefull on it.
I turned the TC01 to obtain the voltage on TO04 6 V, with USB mode and IF SHIFT control fully counterclockwise, and when I switch to LSB and IF SHIFT fully closkwise, it go down a little, 5,5 v.
The document refers it should be 3-4 V.
Any idea?
|
Ohhhh, I found them. I have never seen them before. Very thanks, Mat.
Dr. José Carlos León Ortega UDI- Universidad para el Desarrollo y la Innovación Tel. (591 3) 3422525
Santa Cruz - Bolivia
On Sunday, September 26, 2021, 01:53:11 PM GMT-4, Mat Breton N8TW <i.m.n8tw@...> wrote:
Hi Jose,
Use the SECOND set of schematics in the FT-980 Technical Supplement, which can be found in the "Files" section, not the debugging/alignment schematics which are earlier in the Supplement.
For the IF unit these are located on pages 182 and 183. I usually print both pages out on 11x17, and then align and tape them together.
--
-Mat Breton, N8TW
|
Hi Jose,
Use the SECOND set of schematics in the FT-980 Technical Supplement, which can be found in the "Files" section, not the debugging/alignment schematics which are earlier in the Supplement.
For the IF unit these are located on pages 182 and 183. I usually print both pages out on 11x17, and then align and tape them together.
--
-Mat Breton, N8TW
|
Hi, guys,
I need an IF Unit circuit without black labels indicating voltages and signals.
These labels are over the lines of circuit and I cant to follow the lines of this Unit.
Thanks.?
Dr. José Carlos León Ortega UDI- Universidad para el Desarrollo y la Innovación Tel. (591 3) 3422525
Santa Cruz - Bolivia
|
Re: FT980 dose not recieve
Hi, Mat and everybody,
I have measured something on radio. Here what I found:
In IF UNIT:
In J01 connector--? There are the following signals:? AMW, AMN, CWW, CWN and SSB. Anyone should be on 13,5 V when each mode is selected by the Mode Selector. Well, All are in zero volt. They do not change when the Mode Selector is moved.
In J08 connector-- There are the following signals: -9V, Rx 9V, 13,5 V, 9 V and Tx 9V. All is ok. Tx 9 v is actived in Tx mode.
AF UNIT:
In J10 connector-- There are the following signals: Tx 13,5V, 13,5 V, SSB 9V and 9 V. All is ok, except SSB 9V, when I move Mode Selector to USB and LSB. It is on zero always. The rest is ok.
In J12 connector-- There are the following signals: CW 9V, FSK 5V and FSK 9V/CW 9V. All is zero always, even moving the Mode? Selector to CW and FSK modes.
Even measure the contacts on Mode Selector. It is ok.
Best regards. CP6CL
Dr. José Carlos León Ortega UDI- Universidad para el Desarrollo y la Innovación Tel. (591 3) 3422525
Santa Cruz - Bolivia
On Friday, September 24, 2021, 06:51:49 PM GMT-4, jose carlos leon via groups.io <josecarlosleon48@...> wrote:
Mat,
I removed? the batteries from packed and waited 5 minuts. Then replaced them on pakect and radio did not change.
Even check all signal from input and output in pll and vco on PLL board. All are ok. I am thinking in problem on RF or IF board.
Thanks a lot. CP6CL
El vie., 24 de sept. de 2021 a la(s) 4:26 PM, Mat Breton N8TW <i.m.n8tw@...> escribió: If you can't hear anything o any mode, it is probably not the BFO VCV. When mine was bad I was still able to do AM, FM, & RTTY.
We'll wait back to hear about the RAM reset ...
--
-Mat Breton, N8TW
|
Re: FT980 dose not recieve
Mat,
I removed? the batteries from packed and waited 5 minuts. Then replaced them on pakect and radio did not change.
Even check all signal from input and output in pll and vco on PLL board. All are ok. I am thinking in problem on RF or IF board.
Thanks a lot. CP6CL
El vie., 24 de sept. de 2021 a la(s) 4:26 PM, Mat Breton N8TW <i.m.n8tw@...> escribió: If you can't hear anything o any mode, it is probably not the BFO VCV. When mine was bad I was still able to do AM, FM, & RTTY.
We'll wait back to hear about the RAM reset ...
--
-Mat Breton, N8TW
|
Re: FT980 dose not recieve
If you can't hear anything on any mode, it is probably not the BFO VCV. When mine was bad I was still able to do AM, FM, & RTTY.
We'll wait back to hear about the RAM reset ...
--
-Mat Breton, N8TW
|
N4PL
Mat Breton N8TW