Topband: Heathkit SB-1000

[Louis Parascondola]

SOmetimes many amps require additional padding on 160m  Add another 200pf to what is already there for 160.  It is necessary to put a brass washer around the contact on the wafer that adds in the padding cap on 160m.  See photo of Al-80A on internet to see where it needs to go.  This is a must or else eventually that contact will burn up if it hasen't already.



-----Original Message-----
From: Rich Cariello <rlcariello at verizon.net>
To: Jim Murray <adkmurray at yahoo.com>
Cc: topband <topband at contesting.com>
Sent: Thu, Dec 17, 2015 6:00 am
Subject: Re: Topband: Heathkit SB-1000

Jim,
To get closer to the needed value of the additional transmitting cap I would try to find out the max value of the load cap that came with the amp. Halve the value and that's what I would install. I recall the amp would kind of tune up around 2 mg with max load cap value. Adding an additional 50% cap allowed the amp to tune the hole 160 meter band. Bottom line just put in whatever you have and see what happens. But if you need to go out and buy something then the 50% cap value should do you. 
Rich AA2MF


Sent from my iPad

> On Dec 17, 2015, at 05:33, Rich Cariello <rlcariello at verizon.net> wrote:
> 
> Jim,
> If I remember correctly placing an additional transmitting type cap across the units load cap did the job. Don't remember the value I used. My guess 100 or 200 PF. I used a cap I had in the junk box. You will need to remove the cap in most cases for the other bands. 
> Rich AA2MF
> 
> Sent from my iPad
> 
>> On Dec 17, 2015, at 01:17, Jim Murray via Topband <topband at contesting.com> wrote:
>> 
>> Anybody know how to make an SB-1000 tune properly on 160?  Ok on other bands but doesn't like 160, dummy load or well tuned Inv.L.   Is it a quirk of the amp needing a modification or possibly a bad component?  Saw nothing obvious before putting it to use but have not had the cover off since.Thanks,Jimk2hn
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