I double-checked the scope settings and found I had the wrong measurement selected.? The actual output of the 78L08 is just a hair over 8V, and the switch, Pre-Mix Local socket and the board itself are seeing 7.76V on each band.? Output is 20mV or so peak to peak, although the service manual calls for 300mV PP.??
So far, everything seems correct for voltages.??
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Pre-mix Local board question
I'm trying to diagnose a problem with the higher bands where the VFO display will change to random frequencies while transmitting.??
Specifications for the PB-2153 are 300mV output on Pin 3, where I am seeing about 20-25 mv peak to peak.? The output is at the correct frequency for each local oscillator.? Supply voltage switches properly to each LO pin on the board, but seems low at 5V each band.? Since the collector voltages are listed (for the earlier board, very similar circuits) at 6.6-6.7 volts, 5V supply seems too low.
The board supply comes from a regulated 78L08 chip mounted on the chassis as a heat sink.? It's fed by a 12V output from the Rectifier A board.? It's regulated 8V output goes to the bandswitch segment S1A through a 22 ohm dropping resistor, then from the switch directly to the board pins for each band.? The 22 ohm resistor would be carrying about 136mA to drop the voltage 3 volts, with about .4 watts dissipated, which seems rather a lot.? Also, 5V seems too low for the circuit as described in the service manual.??
I'm about to start tracing the power from the 78L08 to see if it's actually putting out 8V, and where it drops to 5V.??
Any hints, suggestions, lessons learned etc. welcome.
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Rewiring the RL-1 socket is not something I want to do; but the Potter & Brumfield relay is so tantalizingly close to what the FT-101 uses...
Luckily for me, my OM likes to make electronic gadgets and was looking for a new project. We wondered if he could make an adapter that would map the P&B relay pins to the existing socket connectors. He finished it yesterday and it works great. The adapter comprises a socket for the new relay to plug into, two stacked circuit boards that do the remapping, and homemade brass pins that plug into the old socket. The pins were actually one of the tougher problems because he couldn't find any ready-made pins that would fit. We'll keep an eye out for corrosion on those brass pins. Those shiny new relay contacts snapping back and forth make me so happy.
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Re: FT101ZD 10M Only Incorrect Frequency Readout
Thank you Jim. That sounds very plausible. I’ll give it a try.
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On Jun 29, 2024, at 15:05, Jim Shorney via groups.io <jimNU0C@...> wrote:
?
This sounds like an analog problem. You may be losing too much signal amplitude of the LO signal feeding the counter at the higher frequencies. Glancing over the schematic I think i would look at the buffer circuit for the input to the counter. Check the electrolytic caps around Q01, Q03, and Q04. Starting with C10.
Disclaimer, I don't own nor have I ever worked on one of these. This is an educated guess.
73
-Jim
NU0C
On Sat, 29 Jun 2024 06:14:44 -0700
"A. John Hecht via groups.io" <k6koi@...> wrote:
I still have a couple of issues remaining with the "Parts" FT101ZD I'm restoring. It looks like I have a frequency counter issue. The counter works 100% on all bands except on any of the 10 meter band segments. From a cold start it reads correctly; then after about 30 seconds the readout of all 10 meter segments is 600 KHz low (e.g. 28.000 becomes 22.000). The actual received and transmitted frequency remains correct. Other than using DeOxit on the RCA connector to the counter, I've not yet gotten into it. I hate counter issues because I don't understand those circuits very well. Any ideas?
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Re: FT101ZD 10M Only Incorrect Frequency Readout
This sounds like an analog problem. You may be losing too much signal amplitude of the LO signal feeding the counter at the higher frequencies. Glancing over the schematic I think i would look at the buffer circuit for the input to the counter. Check the electrolytic caps around Q01, Q03, and Q04. Starting with C10. Disclaimer, I don't own nor have I ever worked on one of these. This is an educated guess. 73 -Jim NU0C On Sat, 29 Jun 2024 06:14:44 -0700 "A. John Hecht via groups.io" <k6koi@...> wrote: I still have a couple of issues remaining with the "Parts" FT101ZD I'm restoring. It looks like I have a frequency counter issue. ?The counter works 100% on all bands except on any of the 10 meter band segments. ?From a cold start it reads correctly; then after about 30 seconds the readout of all 10 meter segments is 600 KHz low (e.g. 28.000 becomes 22.000). ?The actual received and transmitted frequency remains correct. ?Other than using DeOxit on the RCA connector to the counter, I've not yet gotten into it. ? I hate counter issues because I don't understand those circuits very well. ?Any ideas?
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FT101ZD 10M Only Incorrect Frequency Readout
I still have a couple of issues remaining with the "Parts" FT101ZD I'm restoring. It looks like I have a frequency counter issue. ?The counter works 100% on all bands except on any of the 10 meter band segments. ?From a cold start it reads correctly; then after about 30 seconds the readout of all 10 meter segments is 600 KHz low (e.g. 28.000 becomes 22.000). ?The actual received and transmitted frequency remains correct. ?Other than using DeOxit on the RCA connector to the counter, I've not yet gotten into it. ? I hate counter issues because I don't understand those circuits very well. ?Any ideas??
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Even after a careful online search and checking with my ham friends, I was not able to find the female Jones plug for the AC input to my newly acquired FT101ZD. ?There are six pin Jones plugs out there (Mouser, etc.) but not with one pin having a different orientation (the "Key" pin) ?from the other 5 pins. ?So I took one of my six pin plugs that have all vertical pins and drilled out a pin to make a hole for the Key pin on the FT1001ZD's AC socket; works like a charm. ?Be very, very careful to solder the three wires from an AC cord in the correct locations. ?Usually (not always) three conductor cords have black, white and green wires. ?The black wire goes to the Hot pin; the white wire goes to the Neutral pin and the green wire goes to the Ground pin. You should check your cord by using a DVM . The round pin on a three pronged AC male plug is ground; the narrower flat and vertical pin is hot and the ?wider flat and vertical pin is neutral. ?
Looking at the rear transceiver apron the Key pin is upper right (it's horizontal); the ground is vertical, adjacent and to the left of the Key pin; the neutral is vertical and directly below the ground pin and the hot pin is vertical, adjacent and to the right of the ?neutral pin. ?
I'll try to upload a couple photos (no guarantee).
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I think pretty much any diode can be used as a varactor. Some are just better than others. 73 -Jim NU0C On Sun, 23 Jun 2024 07:45:50 -0700 "A. John Hecht via groups.io" <k6koi@...> wrote: Emerson, do those diodes function as vari-caps?
On Jun 22, 2024, at 7:18?PM, Emerson PP6EW via groups.io <bunhoel@...> wrote:
John
I guess you can replace the varicap by a 1N4001 -1n4007.
Emerson
PP6EW
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Emerson, do those diodes function as vari-caps? ?
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On Jun 22, 2024, at 7:18?PM, Emerson PP6EW via groups.io <bunhoel@...> wrote:
John
I guess you can replace the varicap by a 1N4001 -1n4007.
Emerson PP6EW
Em sáb., 22 de jun. de 2024 às 20:34, A. John Hecht via <k6koi= [email protected]> escreveu: I recently was given two FT101ZD's, one a "Parts rig" Mark I and the other a Mark II.? Both required work but both are now working.? I found I had to remove the voltage to PIN 2 of the VFO input connector to calm down the VFO in the Mark I. The VFO was moving like crazy and when it did settle down it still had an issue with warble.? Removing the voltage solved the issue but now of course the Clarifier function is no longer.? It appears that the variable-cap diode (D01) for the clarifier circuit is defective.? I have some of those diodes on order from China so I'll know soon enough after they arrive.? Has anyone else had an issue with this vari-cap diode??
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Thank you Jim for taking the time to respond to my posting. I agree that a DMM would not detect a very slight voltage variation in the DC, especially if the sampling rate of the DMM is too slow. And even with a scope it would be a challenge to see ripple without very careful adjustment of triggering, etc. So to check the voltage I substituted battery. The warble returned with that voltage. I really think it’s the var-cap diode. We’ll see. I might just leave the voltage off pin 2 of the 4 pin to the VFO and claim success! (Not an elegant solution.)
BTW, I also agree that connectors are always suspect in these old rigs. In fact some of the Molex connectors were I did use De-Oxit on the connectors to and from the VFO.
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On Jun 22, 2024, at 8:35?PM, Jim Shorney via groups.io <jimNU0C@...> wrote:
I recently repaired a FT-707 that had, among other things, clarifier issues. I found that the JFET constant current source and the Zener diode in the clarifier power circuit to be bad. Not flakey, hard failures. The clarifier voltage source must be absolutely stable. More stable that what you can see on the average DMM. After all that the clarifier frequency was lagging behind the action of the knob. It sounded like a capacitive charge curve. I checked EVERYTHING in and around the VFO and clarifier. Including the varactor. It was driving me nuts. It turned out to be the stupid connector that plugs into the VFO.
Check the simple stuff first.
73
-Jim (I hope I never see that radio again)
NU0C
On Sat, 22 Jun 2024 15:10:00 -0700
"A. John Hecht via groups.io" <k6koi@...> wrote:
I recently was given two FT101ZD's, one a "Parts rig" Mark I and the other a Mark II. Both required work but both are now working. I found I had to remove the voltage to PIN 2 of the VFO input connector to calm down the VFO in the Mark I. The VFO was moving like crazy and when it did settle down it still had an issue with warble. Removing the voltage solved the issue but now of course the Clarifier function is no longer. It appears that the variable-cap diode (D01) for the clarifier circuit is defective. I have some of those diodes on order from China so I'll know soon enough after they arrive. Has anyone else had an issue with this vari-cap diode?
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I recently repaired a FT-707 that had, among other things, clarifier issues. I found that the JFET constant current source and the Zener diode in the clarifier power circuit to be bad. Not flakey, hard failures. The clarifier voltage source must be absolutely stable. More stable that what you can see on the average DMM. After all that the clarifier frequency was lagging behind the action of the knob. It sounded like a capacitive charge curve. I checked EVERYTHING in and around the VFO and clarifier. Including the varactor. It was driving me nuts. It turned out to be the stupid connector that plugs into the VFO. Check the simple stuff first. 73 -Jim (I hope I never see that radio again) NU0C On Sat, 22 Jun 2024 15:10:00 -0700 "A. John Hecht via groups.io" <k6koi@...> wrote: I recently was given two FT101ZD's, one a "Parts rig" Mark I and the other a Mark II. ?Both required work but both are now working. ?I found I had to remove the voltage to PIN 2 of the VFO input connector to calm down the VFO in the Mark I. The VFO was moving like crazy and when it did settle down it still had an issue with warble. ?Removing the voltage solved the issue but now of course the Clarifier function is no longer. ?It appears that the variable-cap diode (D01) for the clarifier circuit is defective. ?I have some of those diodes on order from China so I'll know soon enough after they arrive. ?Has anyone else had an issue with this vari-cap diode?
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John
I guess you can replace the varicap by a 1N4001 -1n4007.
Emerson PP6EW
Em sáb., 22 de jun. de 2024 às 20:34, A. John Hecht via <k6koi= [email protected]> escreveu:
I recently was given two FT101ZD's, one a "Parts rig" Mark I and the other a Mark II.? Both required work but both are now working.? I found I had to remove the voltage to PIN 2 of the VFO input connector to calm down the VFO in the Mark I. The VFO was moving like crazy and when it did settle down it still had an issue with warble.? Removing the voltage solved the issue but now of course the Clarifier function is no longer.? It appears that the variable-cap diode (D01) for the clarifier circuit is defective.? I have some of those diodes on order from China so I'll know soon enough after they arrive.? Has anyone else had an issue with this vari-cap diode??
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I recently was given two FT101ZD's, one a "Parts rig" Mark I and the other a Mark II. ?Both required work but both are now working. ?I found I had to remove the voltage to PIN 2 of the VFO input connector to calm down the VFO in the Mark I. The VFO was moving like crazy and when it did settle down it still had an issue with warble. ?Removing the voltage solved the issue but now of course the Clarifier function is no longer. ?It appears that the variable-cap diode (D01) for the clarifier circuit is defective. ?I have some of those diodes on order from China so I'll know soon enough after they arrive. ?Has anyone else had an issue with this vari-cap diode??
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Re: FT 101 EE Audio board
Em qui., 20 de jun. de 2024 às 22:15, James Fisher via <cadiscase= [email protected]> escreveu:
I have an FT 101 EE.
The Audio Board is? PB-1315.
I am replacing the electrolitic caps? and the Mylar caps.
Is there any change in cap values I should make that would improve the audio on transmit or receive ?
I think the FT101 could us a little more bass.?
Thanks?
James
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I have an FT 101 EE.
The Audio Board is? PB-1315.
I am replacing the electrolitic caps? and the Mylar caps.
Is there any change in cap values I should make that would improve the audio on transmit or receive ?
I think the FT101 could us a little more bass.?
Thanks?
James
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Re: Reconversion from 11M Local Oscillator alignment
Only the older ZD models have the display unit with the toggle switches. I can’t remember when the switched over to the later model.?
On Thu, Jun 20, 2024 at 5:40?AM Chuck, WS1L via <chandlerusm= [email protected]> wrote: Would that be the case for a 101ZD MkII?? I've never seen any toggle switches on the VFO although they could be inside the housing. ---------- Forwarded message --------- From: Bruce Collins via <kb0tj1=[email protected]>Date: Wed, Jun 19, 2024 at 12:40?PM Subject: Re: [Yaesu-FT-101] Reconversion from 11M Local Oscillator alignment To: < [email protected]> I’m pretty sure if it is showing MHz ?off, but is actually transmitting and receiving at the right frequency … it has nothing to do with the new 10m crystals.?
The older display units had toggle switches on them that mix signals to give you the right offset displays.?
Maybe better check that out in case it is adjustable.?
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Re: Reconversion from 11M Local Oscillator alignment
Unplug the two wire harnesses from the display unit and clean the male pins. Plug them back in a few times to make sure all of them or connecting well. Retest.? If no good: As lame?as it sounds, I’d buy a new display unit on eBay, swap it out with the one in the radio now and if still no difference, put it back on eBay! You won’t get stuck with it, they sell fairly easily.?
On Thu, Jun 20, 2024 at 5:40?AM Chuck, WS1L via <chandlerusm= [email protected]> wrote: Would that be the case for a 101ZD MkII?? I've never seen any toggle switches on the VFO although they could be inside the housing. ---------- Forwarded message --------- From: Bruce Collins via <kb0tj1=[email protected]>Date: Wed, Jun 19, 2024 at 12:40?PM Subject: Re: [Yaesu-FT-101] Reconversion from 11M Local Oscillator alignment To: < [email protected]> I’m pretty sure if it is showing MHz ?off, but is actually transmitting and receiving at the right frequency … it has nothing to do with the new 10m crystals.?
The older display units had toggle switches on them that mix signals to give you the right offset displays.?
Maybe better check that out in case it is adjustable.?
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Re: Reconversion from 11M Local Oscillator alignment
Thanks for that - is it any clue that this only happens when transmitting and the power is increased?? I was suspecting a supply voltage issue perhaps with the additional drain on TX.
Also, since it happens on 10m, 12m and 15m, I would suspect an issue with the actual display board or VFO board ?
I have had to remove these VFOs a few times over the years and remove the VFO cover, ?to just resolder every single joint on them to get the display to work right again.?
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Reconversion from 11M Local Oscillator alignment
Would that be the case for a 101ZD MkII?? I've never seen any toggle switches on the VFO although they could be inside the housing. ---------- Forwarded message --------- From: Bruce Collins via <kb0tj1=[email protected]>Date: Wed, Jun 19, 2024 at 12:40?PM Subject: Re: [Yaesu-FT-101] Reconversion from 11M Local Oscillator alignment To: < [email protected]> I’m pretty sure if it is showing MHz ?off, but is actually transmitting and receiving at the right frequency … it has nothing to do with the new 10m crystals.?
The older display units had toggle switches on them that mix signals to give you the right offset displays.?
Maybe better check that out in case it is adjustable.?
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Re: FT-101EE installing Processor board PB-1534
James
You can find instruction at
section 6-1.
73 Emerson PP6EW
Em seg., 17 de jun. de 2024 às 15:43, James Fisher via <cadiscase= [email protected]> escreveu:
I just got a FT-101EE.
It has the PB-1534 Processor board installed.
It works good except :
When in transmit and the meter is in the ALC position, there is no movement of the meter.
Yes I have turned the mic gain up CW.
I tried adjusting the ALC on PB-1184? but it makes no difference .? The needle is pined to the right.?
I read where the ALC adjustment is located on PB-1534.
I can move VR2 and it does move the needle to the left, but still no 'uptick' when I modulate USB
Are there issues with installing the PB-1534 in a FT-101 EE? ??
Are there any instructions for installing? the PB-1534 in an EE ?
Thanks
James
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Chuck, WS1L
Jim Shorney
Bruce Collins