Project: Restoring A SONY WM-EX652 Walkman - Contact Cleaning For "Gum Bar" Battery.

I was trying to measure the amount of Play time having both batteries installed on the Walkman, as I saw some information saying that it should reach almost 40h.
In my case it was no longer than 10h, so at some moment I assumed the charger is not working and the "gum bar" is not charged.
I tried to use it without the AA battery extension and it was not working at all.
After measuring the "gum bar" battery I realized that something else is causing this low amount of Play time, maybe a broken or corroded contact.
I removed one of the face plates of the Walkman, as you can see below:

After removing the screws marked with red color I was able to reach the battery housing:

After a closer look I saw the corroded contact:

In order to clean it I used an old tooth brush and contact cleaner, below you can see the result:

Now the unit is working on both batteries, used together or separated. What is left to be done is to count how many tapes I will be able to listen without charging the batteries.

TEAC A-3440: Data Information And Technical Characteristics.

Specifications:

• Track System: 4-Channel Multi-Track Simul-Sync;
• 3 Motors: 
• 1 DC-Servo Capstan Motor;
• 2 Eddy Current Induction Reel Motors;
• 3 Heads:
• Erase;
• Record/Sync;
• Playback;
• Reel Size:
• 26.5 cm (10-1/2");
• 18 cm (7");
• Tape Speed:
• 38 cm/s (15 ips)  (±5%);
• 19 cm/s (7-1/2 ips) (±5%);
• Wow and Flutter (NAB Weighted):
• 0.04% at 15 ips;
• 0.06% at 7-1/2 ips;
• Frequency Response (overall):
• 25 - 24000 Hz (±3dβ/0 VU: 40 - 22000Hz) at 15ips;
• 25 - 22000 Hz (±3dβ/-10 VU: 40 - 20000Hz) at 7-1/2ips;
• Signal-to-Noise Ratio (overall): 55dβ (3% THD level, weighted);
• Harmonic Distortion (overall): 0.8% at normal operating level;
• Stereo Channel Separation:45dβ at 1 kHz;
• Rewind/Fast Forward Time: 140s for 1800ft;
• Inputs:
• 4 Line: 60mV/50kΩ;
• 4 Mic: 0.25mV (-72dβ)/600Ω or more;
• Outputs:
• 4 Line: 0.3V/load impedance: 10kΩ or more;
• 1 Headphone Jack: 8Ω;
• Power Requirement:
• 100/117/220/240V AC, 50/60Hz (EX Model);
• 220V AC, 50Hz (EUR Model);
• 240V AC, 50Hz (UK/AUS Model);
• 117V AC, 60Hz (USA/CND Model);
• Power Consumption: 125W;
• Dimensions (W x H x D):
• 445 x 523 x 235mm;
• 17-1/2" x 20-1/2" x 9-1/4"
• Weight: 25kg (55lbs) net;
• Supplied Accessories:
• Input Output Connection Cords;
• RE-1002 Empty Reel;
• NAB Reel Hub Adapters;
• Spicing Tape;

SONY WM-EX652: Data Information And Technical Characteristics.

Supplied Accessories:

• Battery Case;
• Stereo Headphones with Remote Control;
• Clip (which I don't have, I don't know how it looks like);
• Battery Charger;
• AC Plug Adapter (except European, Arabian and Korean Models);
• Rechargeable Battery (NC-6WM, 1.2V, 600mAh, Ni-Cd);
• Carrying Pouch (don't have it either);
• Rechargeable battery carrying case;

General:

• Power Requirements:
• 1.5V;
• Rechargeable Battery;
• One R6 (AA) Battery;
• Dimensions (W/H/D):
• 108.9 x 79.6 x 23.9mm;
• Weight:
• 140g;
• 225g rechargeable battery, headphones with remote control and cassette inclusive;

Tape Section:

• Frequency Response (Dolby NR Off):
• Playback: 20 - 18000Hz;
• Output:
• Headphones;
• Load Impedance: 8 - 300Ω;
• Power Output:
• 5mW + 5mW (16Ω);

Project: Restoring A SONY WM-EX652 Walkman - Headset replacement.

Because of the time passed, the rubber (black insulation) of the headset became very stiff; the feel of it was also a little bit strange. In the same time, the acoustics of the headset were not so great.

As a consequence, I tried to replace them with a new set, in-ear model.

First step was to identify a suitable headset with 16ohms impedance. I found this model: SONY MDR-E11LPB.

Then I was opening the remote control, as you can see below:

I was unsoldering the old headset and attached the new one:

Now the headset looks like new and it works like new:

During this procedure I learned, from a colleague of mine who helped me, an important lesson: before soldering the new wires, which were covered with special insulation paint, need to be cleaned by a process of “boiling” in soldering cleaning solution. After this process they can be soldered on the circuit board, otherwise, the soldering compound is not creating enough retention on the board, the wires can’t be soldered.

Project: Restoring A SONY WM-EX652 Walkman.

I was planning for some time to get a walkman, I have a lot of tapes and some times I appreciate listening a good tape.

I found over internet, using Okazii.ro, this model: SONY WM-EX652.

You can see below some pictures, and I will get back latter with details and technical data:

The headset comes together with a remote control and there is also a “gum bar” battery and one AA battery extension.

Proiect: Restaurare Magnetofon Rostov 105 - Inchiderea Proiectului.

Titlul spune aproape totul, pentru moment ma opresc aici in ceea ce priveste activitatea mea legata de magnetofonul Rostov 105. Am sa continui insa cu celelalte proiecte incepute si care se afla in diverse stadii de realizare, inca mai caut cateva unelte fara de care nu se poate lucra eficient si corect (un osciloscop de exemplu).
Magnetofonul care a fost subiectul acestui proiect are acum un proprietar nou, un prieten care si-a dorit un Rostov 105 la fel de mult pe cat mi l-am dorit eu. Dorinta mea s-a implinit acum un an si jumatate, a lui ieri. L-am dat cu drag pentru ca stiu ca va fi bine ingrijit si folosit. Am fost impresionat sa vad bucuria pe care i-am facut-o atunci cand l-am adus si sa sa-mi dau seama ca ne plac magnetofoanele din aceleasi motive: intelegem complexitatea lor tehnica, apreciem sunetul cald si complet si ne ajuta sa ne indeplinim dorinte vechi ramase constant in memorie.

Am primit in schimb un deck ONKYO Integra TA-2750. Am sa revin cu date tehnice, dar pana atunci pot spune ca sunt impresionat de silentiozitatea cu care lucreaza si calitatea sunetului redat. Am primit si multe casete cu muzica buna, acum ascult Queen - A Day At The Races, si mi-am reamintit de ce imi place Queen.

In imaginea de mai sus sunt cele doua deck-uri din colectie: ONKYO Integra TA-2750 si TEAC A-480, primul fabricat in 1991 iar al doilea in 1978.

Project: Restoring a TEAC RC-70 Remote Control Unit.

Well… there is some time past since my last post, but this is because I was looking for my next item to add to my collection.

This new item arrived few days ago, from US; found on Ebay… it is the TEAC RC-70 Remote Control Unit for my TEAC A-3440 Reel-To-Reel unit. It took me several months to find one in relative good shape and with a small price.

You can see below how the unit arrived:

Cable needs cleaning, dirty connector, and dirty switch box with a paper label on it:

In order to clean it up I used cleaning solution based on orange peal extract and a soft brush.

The switch box can be open very easy by removing the four side screws.

You can see below how the unit looks like after cleaning: