> The 2 tubes are Motorola 65-83382D02(RF parst list for $240 each)
> There is a vent on back door to top of encloser.
> Inside the vent is a heat sink.(No noticeable blower motor.)
> I try POST the pics.
> Aubrey
--- In [email protected], [EMAIL PROTECTED] wrote:
>
>
> The UHF I remember was 4CX250B's but that was earlier.
>
> Neil
>
> ---- Original Message ----
> From: [EMAIL PROTECTED]
> To: [email protected]
> Subject: RE: [Repeater-Builder] Re: Motorola Micro 1?4 kilowatt
> Repeater
> Date: Mon, 20 Mar 2006 18:33:15 -0800 (GMT-08:00)
>
> >OK - I was sure my book shows a pair of 8560As for VHF. The UHF
ones
> >we had used 8874s.
> >LJ
> >
> >
> >-----Original Message-----
> >>From: [EMAIL PROTECTED]
> >>Sent: Mar 20, 2006 4:34 PM
> >>To: [email protected]
> >>Subject: RE: [Repeater-Builder] Re: Motorola Micro 1?4 kilowatt
> >Repeater
> >>
> >>
> >> Some do ... earlier ones do not ... except on UHF ???
> >>
> >> Neil
> >>
> >>
> >>---- Original Message ----
> >>From: [EMAIL PROTECTED]
> >>To: [email protected]
> >>Subject: RE: [Repeater-Builder] Re: Motorola Micro 1?4 kilowatt
> >>Repeater
> >>Date: Mon, 20 Mar 2006 10:39:34 -0800 (GMT-08:00)
> >>
> >>>I thought these 1/4KW amps used 8560A tubes??
> >>>
> >>>-----Original Message-----
> >>>>From: [EMAIL PROTECTED]
> >>>>Sent: Mar 20, 2006 9:28 AM
> >>>>To: [email protected]
> >>>>Subject: RE: [Repeater-Builder] Re: Motorola Micro 1?4 kilowatt
> >>>Repeater
> >>>>
> >>>>
> >>>> I don't know about the later models but when I was servicing
> >>>> the 100 - 275 - 375 watt transmitters, careful maintenance of
the
> >
> >>>> blower motor was necessary. When you determine the blower
motor
> >>>> seems to be slowing down ( lack of bearing lubrication? ) try
> >>>> that first.
> >>>>
> >>>> If that doesn't do any good, then a trip to the local
electric
> >>>> motor repair/rewind shop is necessary. Early on, I used to
take
> >>>> the entire motor to that shop - later years and since we had
> >>>> 30-35 blower motors in various systems everywhere, I got to
the
> >>>> point of disassembling the motor at our shop and taking the
> >>>> armature to the motor shop for a bearing change. They had
the
> >>>> bearing press, and the skill, we didn't.
> >>>>
> >>>> Hope this helps / others probably have different ideas.
> >Whatever
> >>>> works for you is best.
> >>>>
> >>>>
> >>>> In regards to the pair of 4CX250B's - those tubes require
> >serious
> >>>> air circulation. If the blower motor needs servicing, the
air
> >>>> filter is dirty or the fins of the tubes are plugged with
dirt,
> >>>> the tubes will have a very short life.
> >>>>
> >>>> Remember, keep all contacts on that tube socket very clean,
> >>>> properly tensioned, for best performance and reliability.
> >>>>
> >>>> Another item to be aware of is the 4CX250B filament voltage.
> >The
> >>>> required filament voltage is 6.0 Volts (not 6.3 Volts) at 2.6
> >>>> amperes. Absolute minimum heating time is 30 seconds.
Careful
> >>>> attention to the correct filament voltage will give longer
life
> >>>> than if you don't.
> >>>>
> >>>> I am reading from the RCA loose-leaf lay-flat Vacuum Tube
> >>>> Engineering Manual.
> >>>>
> >>>> The tube, properly installed, requires an air-system
socket ...
> >>>> with the use of a ceramic chimney to direct the air coming
> >through
> >>>> the socket to pass through the plate cooling fins.
> >>>>
> >>>> Hope this helps,
> >>>>
> >>>> Neil - WA6KLA
> >>>>
> >>>>
> >>>>---- Original Message ----
> >>>>From: [EMAIL PROTECTED]
> >>>>To: [email protected]
> >>>>Subject: RE: [Repeater-Builder] Re: Motorola Micro 1?4 kilowatt
> >>>>Repeater
> >>>>Date: Mon, 20 Mar 2006 16:33:14 -0000
> >>>>
> >>>>>Ahhh... the famous Motorola 1/4kw dual 4cx250b final?
> >>>>>Never saw one that held up long term without regular
> >>>>>hands-on service. Hard to keep a blower going in some
> >>>>>of the earlier units.
> >>>>>
> >>>>>You're going to love trouble-shooting the safety interlock
> >>>>>circuits connected to the power supply. Just a bit more
> >>>>>fun than working on an MSY or MHB repeater/base.
> >>>>>
> >>>>>cheers,
> >>>>>skipp
> >>>>>
> >>>>>> "ke4ovn" <ke4ovn@> wrote:
> >>>>>> Hello Group:
> >>>>>> Looking on information on A motorola micro repeater,
> >>>>>> 2 tube final Model Number-B93rcb-31058.On 2meter
> >>>>>> band now, Tube final drop from 250watts to 30 watts.
> >>>>>> Need to find a manual number so I can troubleshoot.
> >>>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>Yahoo! Groups Links
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>Yahoo! Groups Links
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>Yahoo! Groups Links
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>Yahoo! Groups Links
> >>
> >>
> >>
> >>
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> >
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> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
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