[Boatanchors] BC-348...

[Carl]

Check all the tubes for heater-cathode leakage.

Carl
KM1H


----- Original Message ----- 
From: "Adam Liette" <n8yd at woh.rr.com>
To: <Boatanchors at mailman.qth.net>
Sent: Tuesday, July 21, 2009 1:49 PM
Subject: Re: [Boatanchors] BC-348...


>
> My wuestion about the hum issue was the way it starts after the set has
> warmed up a while, but goes away when powered down for 10 - 15 min. I do
> have some experience with vintage sets (need to finish my recap job on the
> Zenith 5-J-217 someday), but I'm hoping to preserve the previous fellow's
> work.
>
> 73,
> Adam, N8YD
>
>
> -----Original Message-----
> From: Lloyd KK7IZ [mailto:kk7iz at cox.net]
> Sent: Tuesday, July 21, 2009 1:21 AM
> To: The Pollacks; 'Adam Liette'; Boatanchors at mailman.qth.net
> Subject: Re: [Boatanchors] BC-348...
>
>
> B- is above the chassis ground on these. Check to be sure it is properly
> wired. Don't remember all the details, maybe someone else will.
> Thanx
> Lloyd  KK7IZ
> kk7iz at cox.net
> 480-620-7145
>
>
> ----- Original Message -----
> From: "The Pollacks" <rinkies at att.net>
> To: "'Adam Liette'" <n8yd at woh.rr.com>; <Boatanchors at mailman.qth.net>
> Sent: Monday, July 20, 2009 10:14 PM
> Subject: Re: [Boatanchors] BC-348...
>
>
>> Nice to see a young guy getting involved in boat anchors!  Maybe they'll
>> be
>> a market for my collection when I shuffle off this worldly inductor!
>>
>> Hum sometimes comes from bad filter caps in that power supply.  I usually
>> just parallel a good one temporarily.  If that doesn't do it, look for 
>> bad
>> grounds through the receiver.  If the ground lugs are fastened with nuts
>> and
>> bolts, sometimes just loosening and tightening will do it.  If there's
>> corrosion, use some emery paper and make sure the connections are shiny.
>>
>> These two things will clear up most of the hum problems.  If not, check
>> for
>> leaky caps, especially in the audio section.  Not a bad idea just to
>> change
>> all the caps.  They're cheap these days!
>>
>> Good luck
>> Ron K2RP
>>
>>
>> -----Original Message-----
>> From: boatanchors-bounces at mailman.qth.net
>> [mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of Adam Liette
>> Sent: Monday, July 20, 2009 9:53 PM
>> To: Boatanchors at mailman.qth.net
>> Subject: [Boatanchors] BC-348...
>>
>>
>> Hello, gang. I've fired up my BC-348 (with a genuine hombrewed by an old
>> timer AC supply), and am reminded of the terrible hum. Is there something
>> in
>> the 348 I might start with, or blame the outboard PS? My old timer 
>> comment
>> is made as I'm 26, and the previous owner is an SK. There's also what
>> seems
>> to be an S-Meter added, and a couple of small toggles. Is there info on a
>> common mod such as this?
>>
>> Thanks and 73!
>> Adam, N8YD
>>
>> ______________________________________________________________
>> Boatanchors mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Boatanchors at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>> ______________________________________________________________
>> Boatanchors mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Boatanchors at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
> ______________________________________________________________
> Boatanchors mailing list
> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Boatanchors at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html