...still a good signal Andy,  better than daytime..

73

Steve

G3XKR

On Mon, Feb 29, 2016 at 10:26 PM, Andy Talbot [email protected] [rsgb_lf_group] <[email protected]> wrote:

 

Its still running, and the old design is holding-up .  I found a circuit diagram in the archives and realise there is yet another bit of bodgery that needs to be sorted if this is to be used for long duration unattended transmissions.

The 12V supply used for the fan and other bits of control circuitry is derived from the input supply by a single LM317 regulator.  That device is specified for 40V maximum across it, so at 50V input gives just a 2V margin.   Nowadays, when I want a regulator from 50V to something low, I use an auxiliary emitter follower to coarsely pre-regulate the input to the main regulator to some lower intermediate and safe value.

Will inform here when it finally goes off tonight

'jnt

On 29 February 2016 at 20:03, John Andrews <[email protected]> wrote:

Andy,

Will be watching!

John, W1TAG

On 2/29/2016 2:16 PM, Andy Talbot wrote:

I've put the signal back on, this time using the new (actually very old)
transmitter.   Running a little over 200 Watts so about 90 - 100mW EIRP

Not entirely sure how long I'll run it for - certainly not overnight.  I
don't think that PA has ever been used in anger - until now

137630Hz   Wolf-10

Andy  G4JNT

__._,_.___

---

Posted by: Steve Elliston <[email protected]>

---

Reply via web post

•

Reply to sender

•

Reply to group

•

Start a new topic

•

Messages in this topic (2)

Visit Your Group

• New Members 1

• Privacy • Unsubscribe • Terms of Use

.

__,_._,___