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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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8th Jun 2019, 5:29 pm | #1 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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8th Jun 2019, 5:44 pm | #2 |
Dekatron
Join Date: Nov 2008
Location: Whittlesey, near Peterborough, Cambridgeshire, UK.
Posts: 3,758
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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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8th Jun 2019, 5:53 pm | #3 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,302
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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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Edward. |
8th Jun 2019, 8:41 pm | #4 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 899
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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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9th Jun 2019, 1:33 am | #5 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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9th Jun 2019, 1:42 am | #6 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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9th Jun 2019, 9:12 am | #7 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
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Re: Hacker CH1200 radiogram
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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Edward. |
9th Jun 2019, 12:31 pm | #8 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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9th Jun 2019, 12:50 pm | #9 |
Hexode
Join Date: Dec 2018
Location: Sheffield, South Yorkshire, UK.
Posts: 364
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Re: Hacker CH1200 radiogram
so how did the buzz test go, did you get the buzz
when touching the cartridge pins? |
10th Jun 2019, 4:36 pm | #10 | |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 899
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Re: Hacker CH1200 radiogram
Quote:
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10th Jun 2019, 4:49 pm | #11 | |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 899
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Re: Hacker CH1200 radiogram
Quote:
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10th Jun 2019, 5:50 pm | #12 | |
Dekatron
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,246
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Re: Hacker CH1200 radiogram
Quote:
Paul |
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10th Jun 2019, 11:18 pm | #13 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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10th Jun 2019, 11:20 pm | #14 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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Re: Hacker CH1200 radiogram
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10th Jun 2019, 11:22 pm | #15 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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Re: Hacker CH1200 radiogram (also RG300)
Now I need an on/off pot. Any idea which will fit?
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10th Jun 2019, 11:26 pm | #16 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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11th Jun 2019, 9:07 am | #17 |
Dekatron
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,246
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Re: Hacker CH1200 radiogram (also RG300)
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 |
14th Jun 2019, 5:50 pm | #18 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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Re: Hacker CH1200 radiogram (also RG300)
Many thanks. New cartridge arriving soon. Fingers crossed it'll solve the silent gram.
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17th Jun 2019, 10:55 am | #19 |
Retired Dormant Member
Join Date: Apr 2010
Location: Exeter, Devon, UK.
Posts: 64
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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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17th Jun 2019, 11:00 am | #20 |
Hexode
Join Date: Dec 2018
Location: Sheffield, South Yorkshire, UK.
Posts: 364
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Re: Hacker CH1200 radiogram (also RG300)
It should have a separate mounting bracket / fixing kit supplied with it.
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