Harvard 990 - 8-Track / Q8 player. Work In progress...

[GeezerJem]

Hi all,

I know, I know, I know it's old tech., but the player referenced in :

https://www.quadraphonicquad.com/forums/showthread.php?16815-Harvard-990-on-Ebay-Is-this-quad

has arrived. It does indeed have a four track head and the required Q8 notch switch in the top front of the cartridge. So far so good ! Strange that there is nothing on the internet (that I could find...) about this piece of kit.....

I've cleaned the head, capstan top and bottom and the motor pulley thingy. The belt seems ok. Currently the Shirley Bassey 'Kiss me, Honey honey, Kiss me' on the Pickwick label is running through the machine, giving the occasional frightening CLUNK ! as it changes track. I did give it a brief listen and both channels were working, which is nice. A bit of distortion but the speakers and the tape quality are unknowns.

All arrived it a box with the original boot sale label '8 Track player & tapes £15 the lot GWO' which is a bit gutting as I paid £49. Plus P&P. Knocked down from a BIN of £59.95 tho'....

Remember folks - boot sales are for bargains !

I'll add some pics when I can get on the big computer...

BTW The cart. is 'grumbling' about once a second. Physically grunting. It's not the player, as I've fooled it into thinking a cart. is there and it's silent. Not tried any others yet. Strange.

Jem.

 

[GeezerJem]

SMOKE OMFG !

Unplugged and left until tommorrow. Could be the newspaper I'm resting it on.

Bah.

 

[Q8]

SMOKE OMFG !

Unplugged and left until tommorrow. Could be the newspaper I'm resting it on.

Bah.

Usually when a Q8 is playing, the smoke is coming from me, not the deck.

 

[GeezerJem]

Usually when a Q8 is playing, the smoke is coming from me, not the deck.

LOL @ Q8

Initial looks says the power amp stage. Melted wires. As I have no speakers hooked up ( but the volume is down ) this could be quite feasible as there's no load. Or the amp's old, dead and gone. No bother as I wasn't planning to use it.

I work in an electronics environment and many years ago I suggested that the 'magic smoke' that all components have inside them be scented. Maybe Strawberry for resistors, Apricot for capacitors etc. Would greatly help in fixing things....

Jem.

 

[Q8]

Initial looks says the power amp stage. Melted wires. As I have no speakers hooked up ( but the volume is down ) this could be quite feasible as there's no load. Or the amp's old, dead and gone. No bother as I wasn't planning to use it.

I work in an electronics environment and many years ago I suggested that the 'magic smoke' that all components have inside them be scented. Maybe Strawberry for resistors, Apricot for capacitors etc. Would greatly help in fixing things....

Jem.

Yeah, I would bipass the amp stage completely since you plan on trying to set this at line level. Although I must wonder, will bypassing the amp put things at line level or would it still need some sort of line level amplification. I haven't looked at your deck yet, but does that have dual outputs? Line level and speaker? It seems there were some Q8 decks that had both options. That would make things a lot easier in this case.

 

[GeezerJem]

Yeah, I would bipass the amp stage completely since you plan on trying to set this at line level. Although I must wonder, will bypassing the amp put things at line level or would it still need some sort of line level amplification. I haven't looked at your deck yet, but does that have dual outputs? Line level and speaker? It seems there were some Q8 decks that had both options. That would make things a lot easier in this case.

It's one of those stand alone devices that only has speaker outputs. I can tap off where the volume controls ( and tone controls ) are and stitch it into a line level, with the relevant resistor divider. This work can only begin where the project has mechanical stability i.e. repeatable head alignment, minimal wow / flutter / instabilities / smoke hehe.

Fortunately the power amp is a separate phenolic pcb. Thas a good smell ( until the smoke ).

BUT ( and it's a big BUTT ) these are the times where I wish I wasn't horrendously colourblind. Will have to enlist the help of SWMBI on this one I think.

Thanks for your input so far Q8 !

Jem.

 

[Quad Linda]

Very possible that the outputs were smoked with no load.

 

[GeezerJem]

Soooo....

Having semi-checked it mechanically and discovered some electrical smoke, this evening has been spent looking at circuit boards. There are two identical boards, one fed from the front channels and one from the rear. The rear has the output stage transistors snipped out and the power rails removed. Someone has been here before ......
Each PCB is two channels with no more than 30 discrete components per channel. My current thoughts are to :
1. Map out the circuits and try to understand them or
b) knock up new circuits x 4 using up to date techniques - low noise op-amps etc.

b) gets my vote so far.

Jem.

 

[fredblue]

Soooo....

Having semi-checked it mechanically and discovered some electrical smoke, this evening has been spent looking at circuit boards. There are two identical boards, one fed from the front channels and one from the rear. The rear has the output stage transistors snipped out and the power rails removed. Someone has been here before ......
Each PCB is two channels with no more than 30 discrete components per channel. My current thoughts are to :
1. Map out the circuits and try to understand them or
b) knock up new circuits x 4 using up to date techniques - low noise op-amps etc.

b) gets my vote so far.

Jem.

definitely b.)..! time to bring that little beaut into the 21st century!

 

[Q8]

I agree. If you are going to go through that much trouble, you may as well get the most bang for your buck!