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Hello
Love this group.
I have a Al-82 that I¡¯m going to replace the band switch. I seem to abused it on 160 and 80 m. Anything over about 250 wants and it wants to arc over. There is a wire that goes through the middle of the band switch. It is coated with a clear insulation type of material. It has arched over to it and made a burn hole in the insulation. My question is when I called to order the band switch should I also replace that coated wire? Is that a special coating for RF or maybe just temperature?
?Thanks ?Murf
n7uvh
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It sounds like the insulation is no good anymore. You need to find some wire rated for high voltage. Did the switch contacts get damaged? Bob. W4JFA
Hello
Love this group.
I have a Al-82 that I¡¯m going to replace the band switch. I seem to abused it on 160 and 80 m. Anything over about 250 wants and it wants to arc over. There is a wire that goes through the middle of the band switch. It is coated with a clear insulation type of material. It has arched over to it and made a burn hole in the insulation. My question is when I called to order the band switch should I also replace that coated wire? Is that a special coating for RF or maybe just temperature?
?Thanks ?Murf
n7uvh
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What makes you think a new switch will not end up the same way? ?That problem is common among those amps especially with the AL1200. ?
On Monday, May 8, 2023, 10:22 AM, Pat via groups.io <n7uvh@...> wrote: Hello
Love this group.
I have a Al-82 that I¡¯m going to replace the band switch. I seem to abused it on 160 and 80 m. Anything over about 250 wants and it wants to arc over. There is a wire that goes through the middle of the band switch. It is coated with a clear insulation type of material. It has arched over to it and made a burn hole in the insulation. My question is when I called to order the band switch should I also replace that coated wire? Is that a special coating for RF or maybe just temperature?
?Thanks ?Murf
n7uvh
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Yes Bob
has burn or arch marks on the switch
. ?I am ordering a new switch and was not sure about that wire. I will ask for a chunk of it also.
? ?
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Could you post a picture?
Andy
On 5/8/2023 2:33 PM, Pat via groups.io
wrote:
Yes Bob
has burn or arch marks on the switch
. ?I am ordering a new switch and was not sure about that wire.
I will ask for a chunk of it also.
? ?
--
"Where the Old Soo crossed the New Soo"
Duplainville, Wisconsin
Web page at:
YouTube Channel:
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Is the switch damaged? ?Those amps when allows to arc for a long time will eat away at the ceramic and it it gets hot enough the switch will crack. ? If it¡¯s just superficial ash flash from arching that can easily be cleaned up as good as new. ?If the contacts aren¡¯t shot, usually a good cleaning and a reflowing of solder is all that¡¯s needed.
On Monday, May 8, 2023, 3:33 PM, Pat via groups.io <n7uvh@...> wrote: Yes Bob
has burn or arch marks on the switch
. ?I am ordering a new switch and was not sure about that wire. I will ask for a chunk of it also.
? ?
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Lou, what's this... 'mystery insulated wire'? ?that runs down the inside of the bandswitch used for ??? ?It could always be replace, and some extra teflon tubing slid over it.?
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Not sure if it'll fit but a solid spark plug wire may be a choice. They're designed not to arc and are running very high voltages. Just a possible option. Bob? W4JFA
On Mon, May 8, 2023 at 10:00?PM Jim VE7RF < jim.thom@...> wrote: Lou, what's this... 'mystery insulated wire'? ?that runs down the inside of the bandswitch used for ??? ?It could always be replace, and some extra teflon tubing slid over it.?
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It looks like it goes from the 160 m tap up to two blocking capacitors I think that¡¯s what they¡¯re called,. I do have the spark gap sacrificial copper tab. I did adjusted a little bit closer. I also did clean up the band switch with some rubbing alcohol and a toothbrush took a lot of the carbon off. Of the backside of the band switch.  
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On Mon, May 8, 2023 at 08:46 PM, Adrian Fewster wrote:
Alpha Wire PTFE Natural Cable Sleeve
Adrian, tnx for the info.? I did not know you could buy it as a sleeve.? Tnx I must have had a bad antenna swr when I was contesting on 160. Having head phones on, and not hearing the fuzz or see it on a meter, I think I need to replace the switch.? I did clean it up. I will test it and see if it can take more then 500 watts rtty on 160 and 80 meters. My blocking? caps dont seem to have any damage I can see.? ?I am not sure how to test them.? I am guessing with a VOM meter and if there is no resistance.. would be bad?? Learning as I go.. I do have a chicken stick and us it. tnx... also tnx to all that has been following the thread.? I am open to all ideas. Murf n7uvh
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Good luck with this post, Adrian !! I¡¯m looking forward to the replies¡¡ ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Adrian Fewster
Sent: Tuesday, May 9, 2023 1:39 PM
To: [email protected]
Subject: Re: [ham-amplifiers] Al-82 questions? If you cannot stop the arcing fit these x 2 ; Those intermittent arcs will disappear, seen / tested? here numerous times on various 3-500z x 2 amps ? 73 ? vk4tux ? On 9/5/23 14:50, Pat via groups.io wrote: On Mon, May 8, 2023 at 08:46 PM, Adrian Fewster wrote: Alpha Wire PTFE Natural Cable Sleeve
Adrian,
tnx for the info.? I did not know you could buy it as a sleeve.? Tnx
I must have had a bad antenna swr when I was contesting on 160.
Having head phones on, and not hearing the fuzz or see it on a meter, I think I need to replace
the switch.? I did clean it up. I will test it and see if it can take more then 500 watts rtty on 160 and 80 meters.
My blocking? caps dont seem to have any damage I can see.? ?I am not sure how to test them.? I am guessing with a VOM meter and if there is no resistance.. would be bad?? Learning as I go.. I do have a chicken stick and us it.
tnx... also tnx to all that has been following the thread.? I am open to all ideas.
Murf
n7uvh
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Murf, this same exact problem was prevalent?in the AL80A, and the LK500 amps with the smaller band switch. That 160 meter grounding ?of the plate padding caps is a point of high RF voltages and circulating currents. ?That buss wire gets so hot if melts the solder on the contact at the band switch. ?The solder melts just enough that it doesn¡¯t quite flow but loosens and drys cold. ?That further exacerbates the condition. ?This is a well known problem with these amps.
On Tuesday, May 9, 2023, 12:50 AM, Pat via groups.io <n7uvh@...> wrote: On Mon, May 8, 2023 at 08:46 PM, Adrian Fewster wrote:
Alpha Wire PTFE Natural Cable Sleeve
Adrian, tnx for the info.? I did not know you could buy it as a sleeve.? Tnx I must have had a bad antenna swr when I was contesting on 160. Having head phones on, and not hearing the fuzz or see it on a meter, I think I need to replace the switch.? I did clean it up. I will test it and see if it can take more then 500 watts rtty on 160 and 80 meters. My blocking? caps dont seem to have any damage I can see.? ?I am not sure how to test them.? I am guessing with a VOM meter and if there is no resistance.. would be bad?? Learning as I go.. I do have a chicken stick and us it. tnx... also tnx to all that has been following the thread.? I am open to all ideas. Murf n7uvh
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toggle quoted message
Show quoted text
On Tuesday, May 9, 2023, 12:29 AM, Pat via groups.io <n7uvh@...> wrote: It looks like it goes from the 160 m tap up to two blocking capacitors I think that¡¯s what they¡¯re called,. I do have the spark gap sacrificial copper tab. I did adjusted a little bit closer. I also did clean up the band switch with some rubbing alcohol and a toothbrush took a lot of the carbon off. Of the backside of the band switch.  
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That wire goes up to the two 170 pf doorknobs in parallel for padding the tune cap on 160. ?That wire runs down to the bandswitch ?and is grounded through the switch completing the padding of the tune cap. ?It¡¯s a point of high RF circulating currents . ?This same issue was prevalent in the AL80A. SB1000 and LK500 amps with the small switch. ?
On Monday, May 8, 2023, 10:40 PM, Bob <W4JFABob@...> wrote: Not sure if it'll fit but a solid spark plug wire may be a choice. They're designed not to arc and are running very high voltages. Just a possible option. Bob? W4JFA On Mon, May 8, 2023 at 10:00?PM Jim VE7RF < jim.thom@...> wrote: Lou, what's this... 'mystery insulated wire'? ?that runs down the inside of the bandswitch used for ??? ?It could always be replace, and some extra teflon tubing slid over it.?
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I have two questions about this.
Lou, Do you just replace the band switch? If so, with what?
Adrian, What is "copper RL"?
Bob? W4JFA
On Tue, May 9, 2023 at 6:39?AM Louis Parascondola via <Gudguyham= [email protected]> wrote:
That wire goes up to the two 170 pf doorknobs in parallel for padding the tune cap on 160.? That wire runs down to the bandswitch ?and is grounded through the switch completing the padding of the tune cap.? It¡¯s a point of high RF circulating currents .? This same issue was prevalent in the AL80A. SB1000 and LK500 amps with the small switch. ? On Monday, May 8, 2023, 10:40 PM, Bob <W4JFABob@...> wrote: Not sure if it'll fit but a solid spark plug wire may be a choice. They're designed not to arc and are running very high voltages. Just a possible option. Bob? W4JFA On Mon, May 8, 2023 at 10:00?PM Jim VE7RF < jim.thom@...> wrote: Lou, what's this... 'mystery insulated wire'? ?that runs down the inside of the bandswitch used for ??? ?It could always be replace, and some extra teflon tubing slid over it.?
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Adrian, That's the type I have in mine. Were there B4 I bought it. I always wondered about them however the amp has no problems. Bob? W4JFA
On Tue, May 9, 2023 at 1:38?AM Adrian Fewster < vk4tux@...> wrote:
If you cannot stop the arcing fit these x 2 ;
Those intermittent arcs will disappear, seen / tested? here
numerous times on various 3-500z x 2 amps
73
vk4tux
On 9/5/23 14:50, Pat via
wrote:
On Mon, May 8, 2023 at 08:46 PM, Adrian Fewster wrote:
Alpha Wire PTFE Natural Cable Sleeve
Adrian,
tnx for the info.? I did not know you could buy it as a sleeve.?
Tnx
I must have had a bad antenna swr when I was contesting on 160.
Having head phones on, and not hearing the fuzz or see it on a
meter, I think I need to replace
the switch.? I did clean it up. I will test it and see if it can
take more then 500 watts rtty on 160 and 80 meters.
My blocking? caps dont seem to have any damage I can see.? ?I am
not sure how to test them.? I am guessing with a VOM meter and if
there is no resistance.. would be bad?? Learning as I go.. I do
have a chicken stick and us it.
tnx... also tnx to all that has been following the thread.? I am
open to all ideas.
Murf
n7uvh
|
Bob, I refuse to change the band switch. ?It will just happen again at some point with a new switch. ?I see this problem all the time in fact just last week. The problem is too widespread to be coincidence. Heavy rtty on 160 seems? to be a common denominator. ?It might even be 160 with poor antenna characteristics. ?If you look back as far as the AL80A you¡¯ll see the same problem however the ¡° corona washer¡± seemed to be a fix on that?amp. ?I¡¯m thinking that washer acted as a heat sink but JI mentioned corona voltages. ? Take your pick.
On Tuesday, May 9, 2023, 7:55 AM, Bob <W4JFABob@...> wrote: I have two questions about this.
Lou, Do you just replace the band switch? If so, with what?
Adrian, What is "copper RL"?
Bob? W4JFA On Tue, May 9, 2023 at 6:39?AM Louis Parascondola via <Gudguyham= [email protected]> wrote:
That wire goes up to the two 170 pf doorknobs in parallel for padding the tune cap on 160.? That wire runs down to the bandswitch ?and is grounded through the switch completing the padding of the tune cap.? It¡¯s a point of high RF circulating currents .? This same issue was prevalent in the AL80A. SB1000 and LK500 amps with the small switch. ? On Monday, May 8, 2023, 10:40 PM, Bob <W4JFABob@...> wrote: Not sure if it'll fit but a solid spark plug wire may be a choice. They're designed not to arc and are running very high voltages. Just a possible option. Bob? W4JFA On Mon, May 8, 2023 at 10:00?PM Jim VE7RF < jim.thom@...> wrote: Lou, what's this... 'mystery insulated wire'? ?that runs down the inside of the bandswitch used for ??? ?It could always be replace, and some extra teflon tubing slid over it.?
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What is a corona washer? Bob
On Tue, May 9, 2023, 8:08 AM Louis Parascondola via <Gudguyham= [email protected]> wrote:
Bob, I refuse to change the band switch.? It will just happen again at some point with a new switch.? I see this problem all the time in fact just last week. The problem is too widespread to be coincidence. Heavy rtty on 160 seems? to be a common denominator.? It might even be 160 with poor antenna characteristics.? If you look back as far as the AL80A you¡¯ll see the same problem however the ¡° corona washer¡± seemed to be a fix on that?amp.? I¡¯m thinking that washer acted as a heat sink but JI mentioned corona voltages. ? Take your pick. On Tuesday, May 9, 2023, 7:55 AM, Bob <W4JFABob@...> wrote: I have two questions about this.
Lou, Do you just replace the band switch? If so, with what?
Adrian, What is "copper RL"?
Bob? W4JFA On Tue, May 9, 2023 at 6:39?AM Louis Parascondola via <Gudguyham= [email protected]> wrote:
That wire goes up to the two 170 pf doorknobs in parallel for padding the tune cap on 160.? That wire runs down to the bandswitch ?and is grounded through the switch completing the padding of the tune cap.? It¡¯s a point of high RF circulating currents .? This same issue was prevalent in the AL80A. SB1000 and LK500 amps with the small switch. ? On Monday, May 8, 2023, 10:40 PM, Bob <W4JFABob@...> wrote: Not sure if it'll fit but a solid spark plug wire may be a choice. They're designed not to arc and are running very high voltages. Just a possible option. Bob? W4JFA On Mon, May 8, 2023 at 10:00?PM Jim VE7RF < jim.thom@...> wrote: Lou, what's this... 'mystery insulated wire'? ?that runs down the inside of the bandswitch used for ??? ?It could always be replace, and some extra teflon tubing slid over it.?
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Pat
Bob