Electronics > RF, Microwave, Ham Radio

Restoration of FT-480R

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Nuno_pt:
Hi,
Today I've found on the dumpster an FT-480R missing some front panel parts.
When I got home plug it and the radio is put in RX mode, but (there is always a but) no display.
With one portable radio I press the PTT and track the signal with the FT-480R, all was good on RX, click the PTT of the FT-480R and the radio is TXing.
First job will be replace all the electrolytic caps, the see what is going wrong with the display.
Will upload the manual and pictures.

 

4cx10000:
I had an FT-480R many years back, I do not even remember when  ::) Anyhow, I also had trouble with the display which I fixed. Think it was a cold solder joint or the DC/DC converter which feeds the display with a minus-voltage-something. Could have mixed up that with the IC-211E because that one was really full of cold solder joints.

Radio Tech:
Nice find  :-+
All mode VHF is rare as hens teeth.

Nuno_pt:
Well on the second time that I turn it on, the display came alive  :clap:, but not for long the digits start to disappear on after the other, and then no dispay  :-//.

The sirvice manual is here < http://www.radiomanual.info/schemi/FT480R_serv.pdf >, will upload some photos tomorrow.

The display is on page 190 and 191 of the PDF.

That show the 7805 (Q28) feeding the 16x 2SA733 (Q03 - Q18), also shows the signal leaving the UPD 1511-011 (Q01), also +13V from T01 after Q30 that feed the display, the middle of the display show -24V that comes back to the T01 (DC-DC converter).

Will have to check all this.

I hope that this is better not be display LD8231/F1P9C5, that is rare, they use to be install in some calculators in the 80's.

4cx10000:
I will have a look att the schematic, and yes, I remember now that it was the -24 volts I hade problem with.

/Sm2GXN

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