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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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17th Apr 2018, 5:43 pm | #1 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Yaesu FT101 early
A friend has brought to me an early Yaesu FT101 with the complaint of no audio on receive.
I have had a look and it looks like the Sanyo STK 401 module is defunct. I will know for sure tomorrow when I knock up an extender for it. In the meantime has anyone here found a solution to this failed module, which of course is NLA. John |
18th Apr 2018, 12:13 pm | #2 |
Heptode
Join Date: Nov 2009
Location: London, Ontario, Canada
Posts: 672
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Re: Yaesu FT101 early
Hi John,
The service manual mentions AN214 as the audio amp IC! The NTE1058 is also equivalent to it. Here is a source for the AN214: http://www.electronic-spare-parts.co.../a/an_214q.htm The FoxTango web site also mentioned that the AN214 was a very reliable IC, for whatever it is worth. EDIT: Correction: Just looked at it again, the AN214 is not for the earliest audio board! You are correct about the STK401! Sorry for the confusion. Regards, Peter Last edited by orbanp1; 18th Apr 2018 at 12:22 pm. |
18th Apr 2018, 12:26 pm | #3 |
Nonode
Join Date: Mar 2005
Location: Nuneaton, Warwickshire, UK.
Posts: 2,033
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Re: Yaesu FT101 early
Harry Leeming, via Practical Wireless, is an expert on older Yaesu gear. Maybe worth contacting him.
Regards Aub
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Life's a long song, but the tune ends too soon for us all. |
18th Apr 2018, 1:39 pm | #4 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,923
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Re: Yaesu FT101 early
If that man cannot sort you, then nobody will. Email in PW or PM me.
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18th Apr 2018, 5:27 pm | #5 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Re: Yaesu FT101 early
Thanks to all for the replies.
Yes I have had a look at the Fox Tango website, what a fund of useful info. Thanks for the comment re Harry Leeming G3LLL I had forgotten all about him, to be honest I thought he had passed away! Oops! FT gives a NTE 1511 as a suitable substitute but it is only available from the USA and I am not sure whether it is a chip or a module. Newark appear to stock it and I can get their parts through Farnell. I need to talk to Harry first. John |
18th Apr 2018, 6:23 pm | #6 |
Heptode
Join Date: Nov 2009
Location: London, Ontario, Canada
Posts: 672
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Re: Yaesu FT101 early
Hi John,
That NTE substitution is an interesting one, with the NTE1511 being a "5–Step LED Driver for Linear Scale". It certainly does not look like the Sanyo chip: http://www.nteinc.com/specs/1500to1599/pdf/nte1511.pdf So those guys at FT must know something that I do not know! My guess would be that this is a typo. I could not find a datasheet for the STK401, only for some later versions that are for high power stereo amps. Also, finally found an FT-101 manual that shows the schematics with the STK401! The STK401 looks like an "op-amp style" power amp. Not knowing what is the value of the internal feedback resistor (that is why you would need the data sheet) one can not calculate the gain. I would hazard to guess that the gain in that application is somewhere between 30dB to 50dB. As a replacement I would use a TDA2003 or similar, and would set the gain to 40dB initially, and would change (fine tune) it as required. Regards, Peter Last edited by orbanp1; 18th Apr 2018 at 6:46 pm. |
19th Apr 2018, 12:31 pm | #7 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Re: Yaesu FT101 early
Hi Peter,
Well suppose it would have helped if I had typed the correct prt nr. NTE1151 D'oh. Senile decay setting in early here. I will contact Harry Leeming to see if he can offer any advice or comments then go from there and report back here. John |
26th Sep 2018, 9:27 pm | #8 |
Nonode
Join Date: Mar 2005
Location: Nuneaton, Warwickshire, UK.
Posts: 2,033
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Re: Yaesu FT101 early
Hi John, did you manage to contact Harry?
Cheers Aub
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Life's a long song, but the tune ends too soon for us all. |
26th Sep 2018, 10:24 pm | #9 |
Heptode
Join Date: May 2014
Location: Salisbury, Wiltshire, UK.
Posts: 998
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Re: Yaesu FT101 early
I rebuilt a dead early 101a few years ago and Harry was a good source of enthusiasm and knowledge. I didn't have your fault though. Good luck
David |
27th Sep 2018, 9:01 am | #10 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Re: Yaesu FT101 early
Yes I did manage to contact Harry who is still going strong.
Unfortunately he no longer has any parts so I returned the unit to the friend as he didn't wish to spend any money on it. John |
27th Sep 2018, 12:07 pm | #11 |
Heptode
Join Date: May 2014
Location: Salisbury, Wiltshire, UK.
Posts: 998
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Re: Yaesu FT101 early
Oh thats a shame. They are lovely bits of kit to use. Still, all good things etc
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