[DMcMahon]

Mk. 5 Series 2 Update:-

Rear cover to humdinger pot (150 Ohm wirewound Linear Egen Type 126) refitted, as had previously fallen out).

Cleaned up heavy tape oxide deposits off the 15 ips capstan shaft sleeve. Cleaned up the pinch roller, there was a felt ring on the underside recess, assume for oil reservoir so added a little oil. Cleaned the the top panel mask.

Replaced a small black plastic P clip that clamped down (at power supply) the sleeved cables going from the power supply to the amplifier with a larger P clip. The black P clip was too small and was tightly crimping down the sleeving, checked wires in the sleeving but not damaged.

Checked Erase operation by selecting Record but recording on tape was not erased. Scope checked and getting good erase and bias signals going to the heads. One strange thing only get the bias and record signals when the tape deck is set to record (amplifier has to be set to record as well). Must be missing something obvious, but cannot see anything on the schematic that explains why the tape deck has to be switched to Record ?

Found 2 reasons why Record setting was not erasing the tape.

1. The tape release pin was fouling the upper head cover, so the L1 pressure pad arm was not not allowing the arm to reach the erase head (cover re-adjusted to clear).

2. The tape is not contacting the erase had due to the L1 pressure pad felt having previously fallen off. By manually pushing the tape to contact the erase head, the recording is then erased.

Cannot currently find the pressure pad, may have to find something suitable to make a new one, the felt pad on the L2 arm (PB/Record head ) is also not in good condition.

Tested recording using a microphone, got good record signal on the EM 87 Magic Eye and could see the record signal modulating the bias signal going to the PB/Record head, but the microphone recording did not play back. The recording may have been masked by the existing recordings, need to try again once erase is working properly.

Exercised fast wind more, sometimes did experience some tape spillage (mainly on rewind) so tried the fast switching to opposite fast wind function before going to stop procedure, probably need to get the technique/timing of this better as it did not always help when there was a spillage.

Also experienced that when the Take Up spool is at least 50% loaded with tape that Fast Forward often fails to start, can get it going quite easily by manually turning either spool. Fast forwarding works fine end to end as long as there is approximately less than 50% of the tape on the take up spool when fast forward is selected. Have read this is quite common with these Brenells.

Using a microphone checked out the straight through amplifier function all OK.

Have now changed over to non back coated 7" tape. Still to find 8 1/4" tape, I did offer up a 8 3/4" tape (which I easily found) but of course it was too large.