we here at mdm radio , anticipating your every need request consulting our website for trim caps.you and we (or is it we'uns) may be surprised.
mdm
The Johanson 30 pf trimmer is very rare in surplus but the 10 pf
trimmers are very common and cheap (as little as 50c-$1 each) in
surplus. I have bought a few hundred over the years, mostly at
fleamarkets. I have used 3 10pf trimmers in parallel to replace the 30
pf trimmers in Sinclair cans. Depending on the mounting arrangement
that may also work with the DB cans. Also the 10pf unit has a much
higher Q than the 30pf trimmer and paralleling them MAY give a higher Q
than the single 30pf unit. From experience it is certainly no worse.
Richardson Electronics also sell Johanson but their minimum qty is 100
pces. Electrosonic in Toronto used to distribute them but no longer
have the account. The single unit price for the 5602 should be in the
$15 range.
Don't be tempted to use trimmers that have a sliding or rotating
connection to the rotor such as the Johnson air trimmers. I tried that
one time and the rf currant thru the joint caused noise and instability
reflected back to the transmitter. The Johanson trimmer uses a bellows
connection from the moveable element to ground that is a solid but
flexable connection.
Just some hints from years of modifying and making cans in my shop.
Burt VE2BMQ
Mike Besemer (WM4B) wrote:
> Greetings all,
>
> I need two air variable capacitors for our DB4060 cans. I contacted the
> company who bought out DB Products and was informed that they don't sell
> parts... but if they did, the price would be $41 each for the caps!
>
> The caps are Johanson 5602 (www.johansonmfg.com) 1 - 30 pf air variables. I
> requested a quote from Arizona Components Company and one other place, but
> expect the get the 'we don't sell in small quantity' response. Google
> hasn't been much help either.
>
> Does anybody have a couple of these in your pocket or know where I can get
> my hands on a couple of them. What about ideas for suitable subs?
>
> -- de WM4B
> Mike
> Kathleen, GA
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]
<*> Your use of Yahoo! Groups is subject to:
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trimmers are very common and cheap (as little as 50c-$1 each) in
surplus. I have bought a few hundred over the years, mostly at
fleamarkets. I have used 3 10pf trimmers in parallel to replace the 30
pf trimmers in Sinclair cans. Depending on the mounting arrangement
that may also work with the DB cans. Also the 10pf unit has a much
higher Q than the 30pf trimmer and paralleling them MAY give a higher Q
than the single 30pf unit. From experience it is certainly no worse.
Richardson Electronics also sell Johanson but their minimum qty is 100
pces. Electrosonic in Toronto used to distribute them but no longer
have the account. The single unit price for the 5602 should be in the
$15 range.
Don't be tempted to use trimmers that have a sliding or rotating
connection to the rotor such as the Johnson air trimmers. I tried that
one time and the rf currant thru the joint caused noise and instability
reflected back to the transmitter. The Johanson trimmer uses a bellows
connection from the moveable element to ground that is a solid but
flexable connection.
Just some hints from years of modifying and making cans in my shop.
Burt VE2BMQ
Mike Besemer (WM4B) wrote:
> Greetings all,
>
> I need two air variable capacitors for our DB4060 cans. I contacted the
> company who bought out DB Products and was informed that they don't sell
> parts... but if they did, the price would be $41 each for the caps!
>
> The caps are Johanson 5602 (www.johansonmfg.com) 1 - 30 pf air variables. I
> requested a quote from Arizona Components Company and one other place, but
> expect the get the 'we don't sell in small quantity' response. Google
> hasn't been much help either.
>
> Does anybody have a couple of these in your pocket or know where I can get
> my hands on a couple of them. What about ideas for suitable subs?
>
> -- de WM4B
> Mike
> Kathleen, GA
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
Ted Bleiman K9MDM
MDM Radio Ltd -
1629-B N. 31 st Ave
Melrose Park, IL 60160
708.681.0300 fax 708.681.9800
web http://www.mdmradio.com -
1629-B N. 31 st Ave
Melrose Park, IL 60160
708.681.0300 fax 708.681.9800
web http://www.mdmradio.com -
Check it now!!
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