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Old 8th Jun 2019, 5:29 pm   #1
roxarama
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Default Hacker CH1200 radiogram (also RG300)

I can't find any into about this model which has a 4-speed Garrard 50 deck and a switchable mono/stereo headshell and cartridge. It originally had a separate speaker cabinet for stereo, but it was wrecked in storage. The unit has short legs which are still around to be reattached. Predictably the radio works superbly with no external antenna. Unfortunately there is now no output from the turntable which had worked flawlessly at all speeds and produced great tone and volume. All info welcome.
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Old 8th Jun 2019, 5:44 pm   #2
Audio1950
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Default Re: Hacker CH1200 radiogram

If the radiogram has been in storage for some time, with all the varying temperatures that occur, it's a fair bet that the cartridge has packed up. If I remember rightly, the cartridge is an Acos GP94 or 96? Whichever it is, they are now obsolete, so a suitable replacement will have to be found. Before going down that road, the cartridge needs to be checked. With the volume turned up to halfway, touch a screwdriver tip onto each of the four contacts on the back of the cartridge (you will have to very carefully slide the connectors back just enough to be able to contact the bare metal with the tip of the screwdriver) Touch the blade with your finger and you should get a loud buzz from the speakers from two of the pins. If you do, then the cartridge is dead, but if you don't get a buzz, the the problem is within the amp. Another possibility is that the selector switch for gram/radio is faulty or dirty, but do the cartridge test first, and we'll go from there.
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Old 8th Jun 2019, 5:53 pm   #3
Edward Huggins
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Default Re: Hacker CH1200 radiogram

I'm not sure how effective the output protection is on this? Maybe best not to run this into the channel used for the seperate (for stereo) speaker, maybe by adjusting the Balance control. It's a lovely unit and worth getting a second speaker for.
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Old 8th Jun 2019, 8:41 pm   #4
kirstyd
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Default Re: Hacker CH1200 radiogram

its a hacker Rg 300 [i have the 200 .electronically the same just cabinet differences.Its correct cartridge is a sonotone as you can see in the photo unfortunately they are hard to come by these days .the one i have belonged to my parents and was bought in 1968 .Inside the sealed speaker enclosures there is an 8 inch goodmans unit and a 3 inch tweeter along with a proper crossover unit [not just a capacitor ] the sound is very good with [according to the service manual ] 12 watts per channel .I dont think running it with one speaker is a good idea though
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Old 9th Jun 2019, 1:33 am   #5
roxarama
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Default Re: Hacker CH1200 radiogram

Thanks so much for your help. But why is it an RG 300 when it is badged as a CH1200? I will try your ideas and bear in mind your warnings. I do have a spare used Sonotone cartridge but the one fitted looks much more modern and advanced. I'll see what markings I can find on it. I mainly want to use it for 78rpm records so I don't really need another stereo. Presumably any speaker of the right impedance will work with it.
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Old 9th Jun 2019, 1:42 am   #6
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Default Re: Hacker CH1200 radiogram

Now that I've seen the photo of the cartridge it does look like the one fitted but it must be a later version than the sonotone spare which I was considering.
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Old 9th Jun 2019, 9:12 am   #7
Edward Huggins
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Default Re: Hacker CH1200 radiogram

Quote:
Originally Posted by roxarama View Post
I mainly want to use it for 78rpm records so I don't really need another stereo. Presumably any speaker of the right impedance will work with it.
Yes, any speaker of 8 ohms (best to check, in case it's 15 ohms) will do to take the load. Or, if pushed, an 8 ohm (15 ohm) dummy load resistor. I do not recommend running this again without a suitable load.
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Old 9th Jun 2019, 12:31 pm   #8
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Default Re: Hacker CH1200 radiogram

Tested the cartridge as advised and it is kaput. Thanks for the help, everyone. Rather predictably as one problem is solved another has appeared: this time the one/off knob has has decided to freewheel and not grip the shaft. Looks like time to ge the back off...and look for a new cartridge. There are a few likely looking sonotones on eBay. I'll let you know how it works out.
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Old 9th Jun 2019, 12:50 pm   #9
BRASSBITS
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Default Re: Hacker CH1200 radiogram

so how did the buzz test go, did you get the buzz
when touching the cartridge pins?
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Old 10th Jun 2019, 4:36 pm   #10
kirstyd
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Default Re: Hacker CH1200 radiogram

Quote:
Originally Posted by roxarama View Post
Thanks so much for your help. But why is it an RG 300 when it is badged as a CH1200? I will try your ideas and bear in mind your warnings. I do have a spare used Sonotone cartridge but the one fitted looks much more modern and advanced. I'll see what markings I can find on it. I mainly want to use it for 78rpm records so I don't really need another stereo. Presumably any speaker of the right impedance will work with it.
The label you have found may be from the missing speaker
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Old 10th Jun 2019, 4:49 pm   #11
kirstyd
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Default Re: Hacker CH1200 radiogram

Quote:
Originally Posted by kirstyd View Post
its a hacker Rg 300 [i have the 200 .electronically the same just cabinet differences.Its correct cartridge is a sonotone as you can see in the photo unfortunately they are hard to come by these days .the one i have belonged to my parents and was bought in 1968 .Inside the sealed speaker enclosures there is an 8 inch goodmans unit and a 3 inch tweeter along with a proper crossover unit [not just a capacitor ] the sound is very good with [according to the service manual ] 12 watts per channel .I dont think running it with one speaker is a good idea though
I have a second head for this machine thats fitted with a BSR SC12M it works very well but its not quite as sensitive as the sonotone
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Old 10th Jun 2019, 5:50 pm   #12
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Default Re: Hacker CH1200 radiogram

Quote:
Originally Posted by roxarama View Post
Thanks so much for your help. But why is it an RG 300 when it is badged as a CH1200?
A while since I looked inside my RG200A, but I think CH1200 designates the chassis type of your instrument and the metal plate would have been attached to the receiver chassis. A similar plate with the serial number for the radiogram as such would have been fixed to the cabinet back but has presumably been lost.

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Old 10th Jun 2019, 11:18 pm   #13
roxarama
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Default Re: Hacker CH1200 radiogram (also RG300)

Yes I wondered whether the CH1200 label is a relic of the wrecked speaker. I'll also check the cabinet back. The main thing is you've identified it as an RG 300 which is a big help. There are NOS Sonotone 9TA HC (G) cartridges available on Ebay so I'll go for that.
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Old 10th Jun 2019, 11:20 pm   #14
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Default Re: Hacker CH1200 radiogram

Quote:
Originally Posted by BRASSBITS View Post
so how did the buzz test go, did you get the buzz
when touching the cartridge pins?
Yes I did. Thanks for the tip. That's the joy of this group. Someone usually knows the answer.
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Old 10th Jun 2019, 11:22 pm   #15
roxarama
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Default Re: Hacker CH1200 radiogram (also RG300)

Now I need an on/off pot. Any idea which will fit?
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Old 10th Jun 2019, 11:26 pm   #16
roxarama
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Default Re: Hacker CH1200 radiogram (also RG300)

I've also taken up the suggestion of turning the balance off for the missing speaker and it sounds even better with all the output coming through the gram speaker. Thanks again.
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Old 11th Jun 2019, 9:07 am   #17
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Default Re: Hacker CH1200 radiogram (also RG300)

Quote:
Originally Posted by roxarama View Post
Now I need an on/off pot. Any idea which will fit?
No pot required, it's just a switch. This one looks promising to me

https://uk.rs-online.com/web/p/rotar...ches/0316800A/

but a second opinion would be good.

Paul
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Old 14th Jun 2019, 5:50 pm   #18
roxarama
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Default Re: Hacker CH1200 radiogram (also RG300)

Many thanks. New cartridge arriving soon. Fingers crossed it'll solve the silent gram.
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Old 17th Jun 2019, 10:55 am   #19
roxarama
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Default Re: Hacker CH1200 radiogram (also RG300)

The new cartridge works but it seems not to be quite the right one: it lacks the brass mount on the old cartridge which fixes it into the headshell of the Garrard Model 50 Mk2. But at least we now know for sure the old cartridge had died. I really don't want to risk £50 by messing about trying to adapt the brand new cartridge, unless you experts recommend that. More delays. Hey ho.
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Old 17th Jun 2019, 11:00 am   #20
BRASSBITS
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Default Re: Hacker CH1200 radiogram (also RG300)

It should have a separate mounting bracket / fixing kit supplied with it.
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