[time-nuts] General Technology Corp model 304b

Ed Palmer ed_palmer at sasktel.net
Sun Apr 29 23:27:04 UTC 2012


Yes, there's a partial copy of the manual online.  It's missing a few 
schematics, but is otherwise complete.

http://sundry.i2phd.com/ServiceManual_304b.pdf

Ed


On 4/29/2012 5:18 PM, paul swed wrote:
> Curious is the manual online?
> Would be interesting to look at.
>
> On Sun, Apr 29, 2012 at 6:33 PM, Ed Palmer<ed_palmer at sasktel.net>  wrote:
>
>> Hi Don,
>>
>> On 4/29/2012 2:54 PM, Donald Henderickx wrote:
>>
>>> On 4/29/2012 1:36 PM, Ed Palmer wrote:
>>>
>>> Thank you Ed,Paul,and Marco for the reply's
>>> The foam I was referring to is or was around ceramic base  were the
>>> igniter wire goes . Yes my wire also broke loose however I do not want to
>>> disassemble any more than I have to. I think that just inserting it back in
>>> to the hole and securing in some way should work. I do not know what the
>>> potential is but I have seen a spark jump at least an eight of an inch.
>>>
>> The igniter wire has to be connected to the base of the lamp.  The patent
>> explains it quite well.  Just inserting it into the hole in the ceramic is
>> unlikely to work.  I don't know what the voltage is, but the capacitor that
>> stores the voltage is rated for 400V.
>>
>> Does the foam look original?  It definitely isn't on mine so I wasn't sure
>> if it was supposed to be there or not.  The patent describes how the base
>> is the coolest part of the bulb.  I don't know if a foam covering is
>> appropriate.
>>
>>   Tell me about the lamp voltage test point. My manual has no mention of
>>> it? Were is it located?
>>>
>> All the test points are described on page 5-3 of the manual.  The lamp
>> heater test point is the sixth one from the top.  Ground is the seventh
>> point.
>>
>>   In you first posting I think you mentioned some grounding problems. On
>>> this unit there is a three pin amp connector on the rear on mine the bottom
>>> pin -20 must be grounded or the unit will not work. The red light will come
>>> on very bright but nothing else works.I believe you can also ground the +20
>>>   this allows this to work in various ground polarity systems IE telco
>>> systems +ground. Perhaps I am wrong.
>>>
>> Do you mean the 3 pin round connector on the back?  That's for an external
>> DC power supply.  It has no other function and grounding the bottom pin
>> (which is ground) shouldn't make any difference.
>>
>> Ed
>>
>>
>>   I have Hp113,Hp115 that caution you on the ground polarity of the systems
>>> you are installing them in. I think all the -20 floats from chassis ground
>>> until they get to that rear plug.
>>> Thanks for foam an fiberglass suggestions.
>>>
>>>> Hi Don,
>>>>
>>>> You know that we're going to be swapping many emails, don't you? :-)
>>>>
>>>> On 4/29/2012 11:16 AM, Donald Henderickx wrote:
>>>>
>>>>> After following Ed Palmer's thread on 304b restoration,I was inspired
>>>>> to get my GTC (tracor) 304b ser#279 going.  It seems that the failure of
>>>>> this unit was the break down of the foam that was wrapped around the vcxo
>>>>> located inside the control box. The vapors or the moisture the foam
>>>>> collected corroded the steel fasteners and caused the switches to become
>>>>> intermittent.
>>>>>
>>>> The foam around my OCXO is still in great shape.  Still spongy and
>>>> providing lots of holding force for the OCXO.  My unit is serial #449.
>>>>
>>>>   The replacement of the foam in the control box is not that much of a
>>>>> problem,what I need help with is what to use around the Rb lamp base. The
>>>>> foam has turned to powder.
>>>>>
>>>> Do you mean foam around the back end of the lamp where the wire lead
>>>> comes out or the foam that surrounds the reflector (#16 in the picture in
>>>> the patent that describes the lamp (3311775))?  My #16 foam is really solid.
>>>>
>>>>   Should I try Home foam sealant? The cell's ,of this seem about the same
>>>>> as the old foam.Will it take the heat?Should I make a fiberglass cocoon to
>>>>> put around the lamp base.
>>>>>
>>>> Read the fine print on the can.  It may list the maximum temperature
>>>> rating.  I'd try a fiberglass cocoon first just because it's easily
>>>> reversible if it doesn't work.  When your unit is running is the lamp test
>>>> point voltage correct?
>>>>
>>>> Ed
>>>>
>>>>   The unit now achieves lock in about an hour. The only other thing I did
>>>>> was to replace the caps in the main supply.
>>>>> Any thoughts on the insulation?
>>>>> Don H




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