Re: VFO TC801 temp compensating trimmer.location
Well. After some discover I did find the real TC801.
?It is accessible after one pulls off the little can below the VFO that contains some mysterious circuity
Then there is a little hole that you can get a tiny plastic? screwdriver in to
adjust it.
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Re: VFO TC801 temp compensating trimmer.location
Hi Fred
The company ELcon has a great VFO stabilizer, especially for the FT-301.
Take a look at the assembly and operating manual here??
You can order here??
73 de Roland, HB9GAA
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VFO TC801 temp compensating trimmer.location
Hi all I have the top cover off on the old FT-301 and thought I would adjust TC801 for less drift. Is this it? Anybody know? Thanks Fred N1DEC 
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Re: Removing FT-301 VFO mechanism ?
Hi Joel
I just received the VFO stabilizer board sold by K4DPK.
I have an old FT-301D from new that always had a slow drift of the VFO.
So I thought I wold try to improve it.
It looks like to connect his unit to the VFO i need to get at
some of the connections to PB1440.
If I follow your VFO removal procedure will I have access to the board?
Thanks
Fred
N1DEC
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Re: FT-301 - A repair journey begins
I took a look at extracting the meter (on it's bracket) from the radio. Sadly, it seems this is not possible without first removing the front panel. That's more work than I want to do at this stage.
On the plus side, I now have the analogue dial '301 working well on RX and TX. I did a major glue job on the thin, SRBP spacer that indexes the pins on the rear of the six-pin 'Tocon' (Miniature Jones-like) connector on the booster. The pin spacing and orientation of the Tocon is not the same as a Jones. I took measurements of the spacer as, if my glue job fails at some point in the future, I will have a go at making a replacement out of some 1.6 mm thick fibreglass board, with slot and hole cutting using a Dremel, or similar.
The '301 produces 100 W+ PEP of SSB on all bands. The stock Yaesu hand mic didn't sound great, so I substituted a Shure 444T and got improved reports. I did have to move the carrier crystals a little to optimise make the best of the (slightly narrow for my tastes for rag-chewing) filter bandwidth. PA bias sounds OK. The RF processor works well - just like I remember the one in my FT-101E. The VFO is incredibly stable.
There's still a way to go fixing up this old rig - the meter; lack of power out on CW; full alignment; making an adaptor so it will key my linear; and possibly more - but I like 'rolling restorations'. What it has shown already is that the results will justify the time spent. When I run out of electronic work to do on it, I might just attempt to give it a fresh coat of paint, something I have never tried.
Regards to all in the group,
Mark, G4FPH.
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Re: FT-301 - A repair journey begins
James,
Thanks for the link. I had looked on eBay UK, but not US. Good to know there are replacements out there across the Atlantic.
I'll look to extract the meter from my radio in the coming days. I see it's on a bracket. Would be great if extraction of the meter on the bracket turned out to be as easy as pulling cards!
Regards,
Mark, G4FPH.
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Re: FT-301 - A repair journey begins
Best wishes, South Hills Amateur Radio Club, Inc. KS3R / W3PIT / N3WX , & January 30, 2024 2:57 PM, "atlasstuff" < g4fph@...> wrote:
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Michael,
Thanks for the reply.
I have not yet adjusted the carrier oscillators. On LSB and USB they sound about right to my ears as is, just listening to band noise and to some stations. I will trace the path for CW to get to the bottom of why RF output is low on TX for that mode.
If you have a booster amplifier that you have broken for spares then I may be back in touch regarding the Japanese 'Jones' plug if I cannot come up with a solution. Likewise the S-meter. Are you in the US?
Regards,
Mark, G4FPH.
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Re: FT-301 - A repair journey begins
Michael,
Thanks for the reply.
I have not yet adjusted the carrier oscillators. On LSB and USB they sound about right to my ears as is, just listening to band noise and to some stations. I will trace the path for CW to get to the bottom of why RF output is low on TX for that mode.
If you have a booster amplifier that you have broken for spares then I may be back in touch regarding the Japanese 'Jones' plug if I cannot come up with a solution. Likewise the S-meter. Are you in the US?
Regards,
Mark, G4FPH.
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Re: FT-301 - A repair journey begins
Emerson,
Thank you for the reference - I see it now. I will move my 50 kOhm microphone out of the way, so I do not connect it by accident and think that the TX is faulty!
Regards,
Mark, G4FPH.
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Re: FT-301 - A repair journey begins
Dear Mark
to question 1 ?mic 500 ohm. You can find at page 7 instruction manual ft - 301.
att Emerson, PP6EW
Em ter., 30 de jan. de 2024 ¨¤s 00:52, atlasstuff < g4fph@...> escreveu:
Hi to all in the group!
I have started to repair an FT-301 that I acquired years ago. Must say I am mightily impressed with how Yaesu built these. Just love the plug-in card system - must surely be a candidate for the easiest radio to get into and fix ever made.
So far, I have it working on receive - and sounding nice. On transmit, and without the booster plugged in on the rear panel, it produces up to 20 W of RF in SSB, but only a disappointing 1 W of RF in CW / FSK / AM. Sadly, the booster has suffered some mechanical damage in that the 'Jones' plug has taken a bash and the paxolin on the rear that retains the pins now doesn't. Might end up having to replace the whole plug.
A couple of questions, if I may:
Q1. Should the impedance of the companion hand microphone be 50 kOhm, or 500 Ohm? I thought I had read somewhere that, like the FT-101 up until the E/F, the microphone should be a Hi-Z type. I have both types here, but the 50 kOhm unit does not drive the '301 TX at all, whereas the 500 Ohm one does with gusto.
Q2. The front panel meter on mine is open circuit. The circuit shows it as a 200 uA FSD unit. Does anyone have experience of taking one apart and making a fix, or am I looking at finding a (unobtanium) replacement?
Regards,
Mark, G4FPH.
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Re: FT-301 - A repair journey begins
H Mark,
Have you adjusted upper and lower sideband frequency. These xtals typically drift out of spec. adjusting the frequency pot will typically not get you there. If you need parts I have plenty of them. You¡¯ll need a good spectrum analyzer or sensitive frequency counter to measure xtal freq. Also the SSB filters drift(xtal based). I¡¯ll need to sweep them to see how far of they are. Verify supply voltages, see schematic for voltages.
Let me know if you need more details.
Michael
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On Jan 29, 2024, at 7:52?PM, atlasstuff <g4fph@...> wrote:
?Hi to all in the group!
I have started to repair an FT-301 that I acquired years ago. Must say I am mightily impressed with how Yaesu built these. Just love the plug-in card system - must surely be a candidate for the easiest radio to get into and fix ever made.
So far, I have it working on receive - and sounding nice. On transmit, and without the booster plugged in on the rear panel, it produces up to 20 W of RF in SSB, but only a disappointing 1 W of RF in CW / FSK / AM. Sadly, the booster has suffered some mechanical damage in that the 'Jones' plug has taken a bash and the paxolin on the rear that retains the pins now doesn't. Might end up having to replace the whole plug.
A couple of questions, if I may:
Q1. Should the impedance of the companion hand microphone be 50 kOhm, or 500 Ohm? I thought I had read somewhere that, like the FT-101 up until the E/F, the microphone should be a Hi-Z type. I have both types here, but the 50 kOhm unit does not drive the '301 TX at all, whereas the 500 Ohm one does with gusto.
Q2. The front panel meter on mine is open circuit. The circuit shows it as a 200 uA FSD unit. Does anyone have experience of taking one apart and making a fix, or am I looking at finding a (unobtanium) replacement?
Regards,
Mark, G4FPH.
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FT-301 - A repair journey begins
Hi to all in the group!
I have started to repair an FT-301 that I acquired years ago. Must say I am mightily impressed with how Yaesu built these. Just love the plug-in card system - must surely be a candidate for the easiest radio to get into and fix ever made.
So far, I have it working on receive - and sounding nice. On transmit, and without the booster plugged in on the rear panel, it produces up to 20 W of RF in SSB, but only a disappointing 1 W of RF in CW / FSK / AM. Sadly, the booster has suffered some mechanical damage in that the 'Jones' plug has taken a bash and the paxolin on the rear that retains the pins now doesn't. Might end up having to replace the whole plug.
A couple of questions, if I may:
Q1. Should the impedance of the companion hand microphone be 50 kOhm, or 500 Ohm? I thought I had read somewhere that, like the FT-101 up until the E/F, the microphone should be a Hi-Z type. I have both types here, but the 50 kOhm unit does not drive the '301 TX at all, whereas the 500 Ohm one does with gusto.
Q2. The front panel meter on mine is open circuit. The circuit shows it as a 200 uA FSD unit. Does anyone have experience of taking one apart and making a fix, or am I looking at finding a (unobtanium) replacement?
Regards,
Mark, G4FPH.
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I am not sure. when I turned the power on the plastic insulation that was around it would start to smoke. I replaced it with a new one and so far all is good. Maybe it was just old and worn out.?
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Hi Ed,
What was the issue that caused the inductor to fail?
Thanks, Michael
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On Dec 22, 2023, at 1:09?AM, Edward Markham - sp226 <edward.mrkhm@...> wrote:
?Does anyone know a suitable replacement for choke L2?? I have a radio that I am trying to repair that has one that is burnt. The parts list in the service manual lists it as a 35 uh choke with a Yaesu part number. I found a 33 uh choke and was wondering if that is close enough in value. Thanks in advance
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Thank you. Fingers crossed
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Hi Ed.
I would think a 33uh should be fine.
Fred
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Does anyone know a suitable replacement for choke L2?? I have a radio that I am trying to repair that has one that is burnt. The parts list in the service manual lists it as a 35 uh choke with a Yaesu part number. I found a 33 uh choke and was wondering if that is close enough in value. Thanks in advance
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Hi ´¡²Ô»å°ù¨¦²õ,
Thank you for sharing the manual.
Michael
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On Dec 14, 2023, at 4:42?AM, ´¡²Ô»å°ù¨¦²õ <andresvidela1@...> wrote:
?Estimado, estos son los dos manuales que yo he encontrado + esquem¨¢tico completo
Saludos
CE1AVF
<Yaesu FT-301D 05282022.pdf>
<FT-301 Instruction and Service Manual.pdf>
<FT-301D Full Schematic.png>
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Estimado, estos son los dos manuales que yo he encontrado + esquem¨¢tico completo
Saludos
CE1AVF
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Fred, N1DEC
Roland HB9GAA
James Mounts
Michael K.
´¡²Ô»å°ù¨¦²õ
