Make sure to check the 10V adjustment FIRST! This affects everything and is
the reason you need to use the PBT to tune in SSB. The Service Manual
covers that well and shows it as the first step. The adjustment pot is on
the power supply board and easy to bump, throwing everything that depends on
the 10V line off. As I mentioned in a previous email, the real solution to
that repeating problem is to replace the adjustment pots on the power supply
board with multi-turn Bourns pots which won't change value when bumped or
vibrated.
73, Floyd - K8AC
----- Original Message -----
From: "Adrian Rees (MW1LCR)" <ree...@btconnect.com>
To: "'drakel...@.zerobeat.net'" <drakelist@zerobeat.net>
Sent: Saturday, December 12, 2009 2:25 PM
Subject: Re: [Drakelist] TR7 Help please
Hello everyone
I have now stripped & cleaned the Molex connectors,and all the connectors
on
the Digital display board.
This leaves
So far my TR7 is now receiving on all bands apart from 28MHz. I injected a
signal on the amateur bands at 1uV and this was certainly discernable.
However, still no 28MHz and now 7MHz appears to be starting at 8MHz and I
press the "down" button twice to get to 7MHz. Changing the band switch up
or
down and then returning to 7MHz does the same...ie 8MHz.So I guess further
board cleaning is called for tomorrow.I'll finish off the connectors and
switches tomorrow.
I tried the RX sie of things and noticed that the PBT is needed to resolve
an SSB signal, so I guess I need to look at that as well.
I'll get the receive side going on all bands first, then look at alignment
&
voltages.
Thanks all for the help so far.
Regards
Adrian MW1LCR
-----Original Message-----
From: drakelist-boun...@zerobeat.net
[mailto:drakelist-boun...@zerobeat.net]
On Behalf Of Adrian Rees (MW1LCR)
Sent: 12 December 2009 09:27
To: 'drakel...@.zerobeat.net'
Subject: Re: [Drakelist] TR7 Help please
Hello everyone
Thank you all for your replies, both on and off list.
I'll start by stripping & cleaning the PC Board connectors, as per the
many
suggestions I received.
Over here in the UK, we have a product called Servisol, which I guess is
the
same as your Dexoit. Both switch & contact cleaners.
The guy I bought the TR7 from had started restoring the radio and had
changed two transistors, before stopping work on it. These were two
transistors are in the power supply section, specifically Q2104 and Q2105
(TIP31).
He had also acquired two spare boards for the radio, an IF Switching board
and what appears to be a interstage RF amplifier, identified by the serial
C3988W on the board.
I'll clean the connectors and see what we have got then.
Since it's a week or two before Christmas, and we live up in the hills,
the
XYL wants to go shopping, so its doubtful I'll achieve much on it today,
although I may have time this evening, between contacts in the UBA Low
Band
contest which is on tonight & tomorrow morning.(I'm running my rebuilt
FT102
& Dentron Linear for a bit of nostalgia !)
Best wishes & many thanks !
Adrian MW1LCR
North Wales.
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