Hanimex General S734-A stereo reel to reel tape recorder
Hello all
I have a Hanimex General reel to reel. It looks about 1960 vintage with 3 speeds (with capstan sleeve like Akai) and manual equalisation switch. It has speakers in a double lid (like Sony of the period). The valves are:- 7025A x2 with external earthed screens. 6AV6 x2 (although one is impossible to reach or read without lots of dismantling!). 12AU7A only 1 (oscillator?) and 6AR5 x2. I have tried to find a circuit diagram or service manual before attempting repairs. But have failed to find anything on the internet apart from one photo on an Australian website. I am using a variac to power it up gently. The symptom is basically - no sound! The mechanism is rather crude but working. The heaters are working and there is HT. I think the record play switch is good as there is a slight pop when working it, otherwise silence either off tape and with line signal input. I am sure it will need capacitors but it is not even humming! Any ideas and circuits |
Re: Hanimex General S734-A stereo reel to reel tape recorder
I think Hanimex was a Dixon's brand.
Have you tried taking voltage readings on the valves, starting with the 6AR5's? |
Re: Hanimex General S734-A stereo reel to reel tape recorder
It could well be Japanese. Who is the valve manufacturer?
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Re: Hanimex General S734-A stereo reel to reel tape recorder
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Seems like a regular lineup of valves so you should find similar circuits to follow. |
Re: Hanimex General S734-A stereo reel to reel tape recorder
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The camera would have come from Camera House (back when they were a nationwide chain, not a single store in Lower Hutt!), but it wasn't their brand. No idea where the desk lamp came from - possibly somewhere like Woolworths General/DEKA. |
Re: Hanimex General S734-A stereo reel to reel tape recorder
hanimex general
Thanks for the suggestions. The machine is Japanese. I do not have a similar diagram to follow. The voltages are as follows, all heaters 5.22 volts ac. I know this is a bit low as I am running it on the variac. (= play) [= record] in all cases. Valve 7025 A Pin 1 A (106 & 116) [1.8 & 1.8] Pin 2 G all zero or close to Pin 3 C (0.6 both) [0 both] Pins 4,5,9 heaters Pin 6 A (18 & 69) [25 & 12] Pin 7 G (2 & 0.2) [2.3 & 3] Pin 8 C (0.5 & 1.6) [2.5 & 2.1] Valve 6AV6 Pin 1 G (1.4 & 0) [2.25 & 1.1] Pin 2 C (1.6 & 0.7) [2.25 & 1.5] Pins 3&4 heater Pin 5 Diode to earth Pin 6 Diode to earth Pin 7 A (87 & 121) [83 & 116] Valve 12 AU7A only one of these Pin 1 A (153) [178] Pin 2 G (60) [66] Pin 3 C (63) [72] Pins 4,5,9 heater Pin 6 A (153) [178] Pin 7 G (78) [66] Pin 8 C (81) [71] Valve 6AR5 I could only measure one of them as output transformer masking the other. Pin 1 G (24) [0.5] Pin 2 C & Pin 7 (21) [13] Pins 3 & 4 heater Pin 5 A (175) [220] Pin 6 G (181) [209] Is the above any help? |
Re: Hanimex General S734-A stereo reel to reel tape recorder
Valve 7025A appears to be a low noise and low hum version of our familiar ECC83 aka 12AX7.
Graham |
Re: Hanimex General S734-A stereo reel to reel tape recorder
5.22 volts is quite low for the heater voltage and will have a significant effect on everything else.
You appear to have rather low voltages on some anodes, together with excessively high (positive?) voltages on control grids. I don't have the circuit in front of me, but this possibly points to leaky inter-stage coupling capacitors. What type of multimeter are you using to take the measurements? |
Re: Hanimex General S734-A stereo reel to reel tape recorder
Hello all.
I have changed all the coupling capacitors and others of the same type. There were 11 0.047uf made by ELNA, all dud, plus a few of other values. The machine is now working but a bit quiet even at full volume. It records and plays. There is a healthy loud hum if the head connection is touched. I have tried another head but no difference. The new voltages are shown on the right (= play) [= record] in all cases as before. Valve 7025 A Pin 1 A (106 & 116) [1.8 & 1.8] now (141 & 139) [142 & 137] Pin 2 G all zero or close to now still zero Pin 3 C (0.6 both) [0 both]. now (0.9 both) [0.9 both] Pins 4,5,9 heaters. now all 5.5 Pin 6 A (18 & 69) [25 & 12] now all 115 Pin 7 G (2 & 0.2) [2.3 & 3] now all zero Pin 8 C (0.5 & 1.6) [2.5 & 2.1]. now all 0.9 Valve 6AV6 Pin 1 G (1.4 & 0) [2.25 & 1.1]. now all about 0.06 Pin 2 C (1.6 & 0.7) [2.25 & 1.5]. now all about 1.2 Pins 3&4 heater Pin 5 Diode to earth Pin 6 Diode to earth Pin 7 A (87 & 121) [83 & 116]. now all about 160 Valve 12 AU7A only one of these Pin 1 A (153) [178]. now both 206 Pin 2 G (60) [66]. now (26) [31] Pin 3 C (63) [72]. now. (43) [52] Pins 4,5,9 heater Pin 6 A (153) [178]. as pin 1 Pin 7 G (78) [66]. now (25) [32] Pin 8 C (81) [71]. now (42) [53] Valve 6AR5 Moved transformer away to measure both. Pin 1 G (24) [0.5]. now (0.3 & 0.4) [0.02 & 1.1] Pin 2 C & Pin 7 (21) [13]. now all about 13.5 Pins 3 & 4 heater Pin 5 A (175) [220]. now all about 224 Pin 6 G (181) [209]. now all about 227 These look much better to me. Any further ideas? Also I notice the motor gets very hot, too hot to hold your hand on for long. Some websites imply this could be normal for a 60 Hz designed motor running on 50 Hz. Is it normal and is there some way of reducing the heating? Buy the way my meter is Precision Gold PG017 from Maplin. |
Re: Hanimex General S734-A stereo reel to reel tape recorder
hello all
Everything is now resolved. New low voltage capacitors to the cathodes fixed the volume problem. The motor overheating was no more than somebody had put the fan the wrong way up. The shaped blades facing the correct way made a huge difference. An interesting one to remember. Some minor adjustments to the jocky roller and a new drive belt fixed the mechanism. Now working as well as can be expected for a machine over 50 years old. |
Re: Hanimex General S734-A stereo reel to reel tape recorder
Well done getting this far! If playback is quiet, yet you get a healthy loud hum when touching the playback head connection, it could be that playback is fine but the recording level on the tape is low, or the tape is of poor quality - they varied enormously - or that the bias level is incorrect. If you've moved the head alignment or azimuth, that is critical too.
Do you have a known good pre-recorded tape to act as a test source? I have some 3.75 IPS commercially-recorded half-track mono tapes on 5" reels which make good test sources, in the absence of a standard test tape. I could send you one FOC if it would help. |
Re: Hanimex General S734-A stereo reel to reel tape recorder
Thanks for your encouragement. I do have some tapes for testing thanks. I even have a vintage SRT 14 tape for head alignment although it is rather worn out. I am pleased with it now and it it looking good.
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Re: Hanimex General S734-A stereo reel to reel tape recorder
General in the model name could possibly refer to Fujitsu General, but that's just a guess. If you'd like to know the manufacturer, you could try and see wheter there are any marks, codes or logos on motors, transformers, the copper side of any pcbs. Also if it says "Made in Japan" or "Japan" somewhere on the back plate or label, look for a small number right behind it. That usually refers to the manufacturer.
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