Yeasu ft101zd (Yaesu FT101ZD).

[kernowcam]

I have picked up two Yaesu FT101ZDs fairly cheap and need some advice on refurbishing them. I think I have the receivers sort of working on a bad aerial but need some general advice on how to proceed. I have a mate who is 86 and very good so will be handing them over to him soon but wanted to do a few jobs to start with.

I have been cleaning contacts with contact cleaner, as there is some corrosion, by taking all the removable boards out. Some of the pots are improving with the same treatment.

The mode switch seems to be triggering a relay when switched over AM to CW etc.

The dimmer/lighting is all off on one set.

I decided to open the high voltage shield and although the power was off and disconnected for and hour had a tickle from the power still there!

Any advice/links please?

[Alistair D]

Be very aware that the voltages inside the cover are lethal. You have already noticed the the power supply caps have held charge for an hour after being switched off. I am not familiar with your set but you need to look at the schematic to see if there are bleed resistors across the HV electrolytics that should be discharging them in a few seconds.
My other suggestion is to search the internet for how to make a discharge probe. That way you will know that it is safe to carry on delving.

Al

[kernowcam]

I had been told and thought that after one hour it would be discharged, but it caught me out. I think my trouble is I have done very little with valves. I am a bit put off and am going to hand it over to my tame expert, lesson learned, but will get him to talk me through the safety side.

I have not had a detailed look at the diagram but seem to be a lot of relays in there.

[GMB]

*WARNING* If the bias pot on the power board has problem a with contact between slider and track the result is a massive melt-down of the PA valves.

I strongly suggest you wire a resistor between the slider and the negative supply so that if there is a problem the bias goes more negative and thus prevents disaster.

Originally Posted by kernowcam

The mode switch seems to be triggering a relay when switched over AM to CW etc.

Mine does something like that when engaging AM mode if VOX is engaged - which is also how it auto-keys for CW. I think it is just because it makes a clunk on the audio which triggers the VOX.

[kernowcam]

I am well pleased. All the removable boards now have clean contacts and the radio is really springing to life. Seems to be receiving quite well. Audio output is full not 25%. Planning to do a few cosmetic 'safe' jobs now like cleaning etc.

I have to leave the TX side as my wife tells me to sign my will first! Still wondering why all the meter lights are out and the display is dim. I had a look at the diagram but come to a halt. The pot is working and responding to a DMM.

[Richard675]

The meter lights are out possibly because the bulb has blown. I have a 101Z from new in 1982 and I have always had the dimmer on minimum and so far the bulbs have lasted. These can be replaced with white LEDs with an appropriate series resistor.

[kernowcam]

I like the LED idea. I suspect the power feed to the bulbs has gone down as all of the bulbs are out, the dimmer is not working and the display is low.

[kernowcam]

Decided to apply some logic today, working safely. Checked out the main 12/8/5 voltage regs etc and noticed four wires not connected to the main regulator board. Reconnected them, three earths and one 12V feed and the set is now a goodun. Tidied a few items and am well pleased with it.

Off to see my mate to check the TX and line up. Brilliant.

[kernowcam]

Been to see Willie over the weekend.
All sorted / tested and looks like it is a good set. Well pleased, just need a decent aerial and acc plug.
I have been briefed on making the set safe for working as well.

[BrianS1]

L9 connections in the FT101ZD Mk 3 manual are shown as connecting between moving contact of RL2 and PL259 type socket antenna input.
On my FT101ZD I found the " RL" end of L9 connected to the RL2 coil D6 cathode end.

The transceiver had been used in transmit mode.

The addition of L9 was a modification beginning with production lot 4 and was not shown connecting to coil of relay in manual.

I am puzzled and before I solder L9 to the mc pin on relay RL2 would welcome any comments.

[Peter.N.]

The 101ZD is a brilliant radio with reciever sensitivity on a par with most modern sets, the audio quality is also excellent. I had one of these as my first HF rig and apart from drifting on warm up, I prefer it to anything I have had since.

I would also confirm the electric shock risk, having been a TV engineer on valve sets I have probably had thousands of shocks but nothing like the one I got from the top caps of the PA valves on that - with it turned off! It burnt to holes in the ends of my fingers.

One of the greatest advantages is that you can repair them yourself, I did several jobs on mine. Enjoy it.

Peter

[Radio Wrangler]

The only showstopper in the 101ZD is the death of the counter control chip. Unobtainium.

The 101Z and 101ZD are cut-down versions of the FT901 (another decent set) and have much less similarity to earlier radios in the FT101 series.

Getting enough sensitivity for the HF bands hasn't been difficult for a long time, the problem lies in avoiding overload from strong stations, and now the high power broadcasters are running away to the internet, things are getting easier.

The FT107 is pretty much the same series of radio, but with semiconductors throughout.

If you're into restoring FT101 series radios, search out the writings of Harry Leeming G3LLL who probably knows more about them than anyone at Yaesu.

David

[Restoration73]

I have the very late one mk3 (1981) which has FM. Only fault is the sticking c/over relay.
The display problem has an easy solution. Early sets don't have WARC implemented.
http://zl1rod.org/documents/Manuals/...ter%20Unit.pdf

[M3CVU]

Just so you know the display chip can be easily replaced.

Check out Teruhiko Hayashi (JA2SVZ)

http://homepage3.nifty.com/RadioGaGa...R_e/index.html

Regards - Paul (M0TVU) - My ZD is used daily.