[ARC5] Steps to take in bringing an ARC5 Rx back to life
Tom Bridget’s
tarheel6 at msn.com
Fri Apr 3 11:12:27 EDT 2020
Sent from my iPad
> On Apr 3, 2020, at 2:59 AM, arc5-request at mailman.qth.net wrote:
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> Today's Topics:
>
> 1. BC-453 Question BC-454 Also (Whitebear1122)
> 2. Change two resistors and have the BC-456 working great?
> (Tom Bridgers)
> 3. Re: BC-453 Question BC-454 Also (Dennis Monticelli)
> 4. Re: BC-453 Question BC-454 Also (Rich Post)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 2 Apr 2020 22:26:57 -0500
> From: Whitebear1122 <whitebear1122 at comcast.net>
> To: ARC-5 <arc5 at mailman.qth.net>
> Subject: [ARC5] BC-453 Question BC-454 Also
> Message-ID: <24BA2861-35CC-4A50-A90A-E023FEC55F1A at comcast.net>
> Content-Type: text/plain; charset=utf-8
>
> Today I brought in from the garage a BC-453 that has been sitting out there for several years. It has been sitting in an old timers basement since the early 60?s so it was gunky with grime. So I had to clean it up before I wanted to get to close to it.. It cleaned up nicely with some GOJO and a tooth brush, and looks great.
>
> I?m thinking of building a Q5?er with it.
>
> Question for you experts: How would you approach powering this up? One option is to just plug it into a variac and slowly bring it up and find out what happens. Another approach would be to disconnect all the 0.05 or 0.5 cans and measure capacitance and leakage current. Another approach is to shot gun replace those caps.
>
> I know there has been a lot of discussion about recapping the BC-348 Micamold caps and just getting it over with. What about the ARC5 receivers? What has been your experience?
>
> Thanks, Scott WA9WFA
>
>
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 3 Apr 2020 03:46:15 +0000
> From: Tom Bridgers <tarheel6 at msn.com>
> To: ARC 5 list ARC5 <arc5 at mailman.qth.net>
> Subject: [ARC5] Change two resistors and have the BC-456 working
> great?
> Message-ID:
> <BY5PR19MB3617CC3308E33586179D8E3990C70 at BY5PR19MB3617.namprd19.prod.outlook.com>
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> This statement "change two resistors and have your BC-456
> singing again" is backed up by an image which I couldn't find.
>
> Would someone be willing to send me the image and copy
> the list for others who might want it?
> Thanks,
> -Tom KE4RHH
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> ------------------------------
>
> Message: 3
> Date: Thu, 2 Apr 2020 22:13:27 -0700
> From: Dennis Monticelli <dennis.monticelli at gmail.com>
> To: Whitebear1122 <whitebear1122 at comcast.net>
> Cc: ARC-5 <arc5 at mailman.qth.net>
> Subject: Re: [ARC5] BC-453 Question BC-454 Also
> Message-ID:
> <CADgAsSTAbzocFFOt9kywuC4a=E71HKjYLK3vH9ueH7YxfSXA+Q at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Scott,
>
> A quick way to assess your caps is to remove the chassis attachment screw
> from each flower pot one at a time, slip a business card between the can
> and the chassis, and then insert a current meter. Slowly increase the B+
> and see what you've got. Leakage wise the odds are your caps cannot handle
> the full voltage but might be OK running with reduced voltage. Others have
> successfully operated their rigs that way. FYI. I ended up replacing all
> of mine in a BC-453. It now draws 10mA on the 60V I choose to run it on.
> Works great.
>
> Dennis AE6C
>
>> On Thu, Apr 2, 2020 at 8:27 PM Whitebear1122 <whitebear1122 at comcast.net>
>> wrote:
>>
>> Today I brought in from the garage a BC-453 that has been sitting out
>> there for several years. It has been sitting in an old timers basement
>> since the early 60?s so it was gunky with grime. So I had to clean it up
>> before I wanted to get to close to it.. It cleaned up nicely with some
>> GOJO and a tooth brush, and looks great.
>>
>> I?m thinking of building a Q5?er with it.
>>
>> Question for you experts: How would you approach powering this up? One
>> option is to just plug it into a variac and slowly bring it up and find out
>> what happens. Another approach would be to disconnect all the 0.05 or 0.5
>> cans and measure capacitance and leakage current. Another approach is to
>> shot gun replace those caps.
>>
>> I know there has been a lot of discussion about recapping the BC-348
>> Micamold caps and just getting it over with. What about the ARC5
>> receivers? What has been your experience?
>>
>> Thanks, Scott WA9WFA
>>
>>
>>
>>
>> ______________________________________________________________
>> ARC5 mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/arc5
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:ARC5 at mailman.qth.net
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>> This list hosted by: http://www.qsl.net
>> Please help support this email list: https://www.qsl.net/donate.html
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> ------------------------------
>
> Message: 4
> Date: Fri, 3 Apr 2020 02:59:23 -0400
> From: Rich Post <kb8tad at gmail.com>
> To: Whitebear1122 <whitebear1122 at comcast.net>
> Cc: ARC-5 <arc5 at mailman.qth.net>
> Subject: Re: [ARC5] BC-453 Question BC-454 Also
> Message-ID:
> <CAEJr0Fv3vSg7T=9Jb6w_eFoE=pWBbVKxj7qRAUMNkuRQ4V8xeg at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi Scott,
>
> Your mileage will vary. I recently brought a couple of these back to
> life. I had acquired an ARC-5/ R27 and a Navy ARA CCT-46104, roughly
> equivalent to the R-24. Both very unhacked. The R-27 still had its
> dynamotor. I used a variable regulated B+ to power each with the 24 volts
> of filament supplied by a separate transformer. Gently raising the
> voltage up by way of the variable supply, the R-27 powered up unmodified
> right to 250 volts at a measured 48 mA. Very little is to be gained from
> these beyond about 130-150 volts DC. I had to turn the volume down even
> with a B+ voltage of only 150 VDC at a draw of 27 mA. I decided to leave
> the R-27 in its good working unrestored condition, operating it at that
> reduced voltage.
>
> The ARA, on the other hand, was already drawing 50 mA at only 50 volts.
> I throttled the voltage back so that the set was only getting 25 mA. After
> a few minutes, I was surprised to be able to crank the voltage up to 135 at
> that 25 mA but the magic didn't last. One of the potted cap sections
> decided to become a 700 ohm resistor. I replaced that cap section and
> powered it again, measuring the voltage on each of the cap sections and
> disconnecting all that saw more than 6 volts, replacing them with tiny new
> caps using the original wires wherever possible, mounting the new pieces on
> the unique little terminal strips in the center so that the restoration
> could be reversible if I decided to restuff the little pots in the future.
> After the cap replacements, the ARA ran at the same 250 at about 48 mA or
> my B+ preference of between 130-150 volts. I tried several solutions for
> the B+, ending up building a voltage multiplier off the 24 VAC filament
> supply.
>
> I have a couple of already hacked "Q-5'ers" that need to be revived. Time
> for some more experiments.
>
> 73 de Rich KB8TAD
>
> On Thu, Apr 2, 2020 at 11:27 PM Whitebear1122 <whitebear1122 at comcast.net>
> wrote:
>
>> Today I brought in from the garage a BC-453 that has been sitting out
>> there for several years. It has been sitting in an old timers basement
>> since the early 60?s so it was gunky with grime. So I had to clean it up
>> before I wanted to get to close to it.. It cleaned up nicely with some
>> GOJO and a tooth brush, and looks great.
>>
>> I?m thinking of building a Q5?er with it.
>>
>> Question for you experts: How would you approach powering this up? One
>> option is to just plug it into a variac and slowly bring it up and find out
>> what happens. Another approach would be to disconnect all the 0.05 or 0.5
>> cans and measure capacitance and leakage current. Another approach is to
>> shot gun replace those caps.
>>
>> I know there has been a lot of discussion about recapping the BC-348
>> Micamold caps and just getting it over with. What about the ARC5
>> receivers? What has been your experience?
>>
>> Thanks, Scott WA9WFA
>>
>>
>>
>>
>> ______________________________________________________________
>> ARC5 mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/arc5
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:ARC5 at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: https://www.qsl.net/donate.html
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