2m Dick Smith Amp K-6313 info wanted

[ZL3MH]

Bill, What do VHF Ceramic trimmers
look like ? I used some very miniture tuning
plated caps on my 432MHz amp 30 to 120 w
There is a pic on this back a few posts ?

73 Murray

[VK5ACY]

Bill, What do VHF Ceramic trimmers
look like ? I used some very miniture tuning
plated caps on my 432MHz amp 30 to 120 w
There is a pic on this back a few posts ?

73 Murray

Yes Murray, that style of trimmer but physically maybe twice the size or a bit more..

My trimmers came from an early solid-state airband base transmitter bought from Robbie's
shop in (Port) Adelaide late last century....nice trimmers.

[ZL3MH]

Is this the type of trimmer I should be looking for ?

Murray ZL3MH

[VK4TI]

Is this the type of trimmer I should be looking for ?

Murray ZL3MH

http://www.johansonmfg.com/ceratrim-tri ... citors.php

[VK5ACY]

Is this the type of trimmer I should be looking for ?

Murray ZL3MH

Those little trimmers look like they would be about 2-10pF and better suited to UHF service,
with likely inadequate C for the 144MHz PA. If paralleled with fixed capacitors you might get
them to peak but a bigger trimmer would be 'nicer' to use.

The trimmers on the collector tuned circuits have to handle around 50-60W and the Philips
Mylar trimmers would/should be OK to use....like in the attached picture. I have used such
trimmers at UHF with similar power levels - nothing caught fire... and they are quite stable.
I include a BNC connector to give an idea of the physical size - you'll want the larger of the 2 types,
which are about 5-40pF or so.. I reckon they might be from High-Band VHF Mobile radio PAs.

I hunted the junkroom but can't locate any more ceramic VHF trimmers - which are in
principle similar to your small trimmers. My trimmers were about 12 X 15mm and ~ 40pF with
about 0.5mm airgap. If such airgap trimmers are used you must not let any conductive
tuning tool slip off the slot - there's 14 VDC (fed by a fat fuse) across these trimmers.

You just need to find a trimmer which will physically fit and behave itself. My junkroom has limits..

[ZL3MH]

2m PC Boards made, the project moves on slowly

ZL3MH Murray

[VK4GHZ]

Murray, how did you tin the board?
The coverage looks reasonably even, and quite nice.

Secondly, I gotta ask. What's the gunk in the small tin above the PCB?

[ZL3MH]

Tined with low temp solder and solder paste and
a wiping rag

73 Murray ZL3MH

[ZL3MH]

Progress is very slow

At the moment I am hunting through the Tait Rt
boards . I am using the small metal clad caps on
the input and brand new ones on the output using
the bigger Uneco metal clad caps.

Two things I have done . I meggered each part of
the PC Board and each second hand cap with a 500v
megger. Out of 8 small metal clad caps I have found
one that is hard down. The PC board tracks on one
board needed scraping with a very narrow file to
get the megger results up to 200+ Megs. It must be
something to do with the Ammonium Persulphate
staying on the small PC tracks that ate edged out.

73 Murray

[VK5HP]

Do you have a copy of the art work you could post on line?

[ZL3MH]

No I do not have the art work for the PC Board. Look further back on the forum to
see how I made the pc Board.

Bye Murray ZL3MH Murray

[VK3ALB]

There's one on ebay right now. Not mine and I don't know the seller.

200940940375

[VK5ACY]

Do you have a copy of the art work you could post on line?

Hello Paul....

...earlier in this thread you may have read that I have here a spare new PCB for the DSE K-6313 VHF PA.

If you want it it can be yours - free of charge - if you are going to use it.

I might also have the PA control relay in my junk room...

Bill VK5ACY
BOWHILL
PF95sb

[VK5HP]

Thank you Bill, Pm sent.

[VK4CZ]

And I just saw that there's one on eBay currently too:

http://www.ebay.com.au/itm/Dick-Smith-V ... 0940940375

[VK5HP]

dowhttp://www.vklogger.com/forum/downlo ... ew&id=3184

Thanks to Bill Vk5ACY for the board, I have scanned the board and uploaded the images.

[VK5ACY]

As some in South Australia will know...the old and historically significant Bowhill General Store and Post Office burnt down on Saturday night 13th July 2013.

The Owner/Manager was out at the Football Club with his wife and four young children after Saturday's local game so no injuries were recorded.

A local business - Bowhill Engineering - has very kindly offered room for our local Post Office to remain in the area. I found this out on Tuesday after
driving the 22km to Mannum expecting to find my mail at the Post Office in the 'big village'.

What amazes me is that Paul VK5HP has received the PCB already (Wednesday) when I only posted it at 1230 pm on Tuesday...I thought only bills
moved that fast via mail...

Paul VK5HP - when you start looking for bits and pieces for your 2m PA I might be able to help you with some of them.

Bill VK5ACY
BOWHILL
PF95sb

[VK5HP]

Hi Bill, VK5ACY

The part I can't find so far is the 2 coaxial relays.

PM Sent Bill VK5ACY

[VK5HP]

Would these Trim Caps be suitable for the amp ?

http://www.ebay.com.au/itm/Trim-Capacit ... 20b744c854

Or http://australia.rs-online.com/web/p/va ... s/0381419/

[VK5ACY]

I reckon I would use the PANASONIC trimmers.

If you couldn't find your coaxial relays I can let you have my 2 remaining spares.