Mode Zero

Well I have been very fortunate having been given a Ripmax Pathfinder Valve Tx and Rx. The Tx is still in its box.
I am flummoxed by the transmitter . It has two push to make buttons on the front and a curious connection for what can only be the aerial.

Perhaps one of the push to make buttons should stay locked down. In other words the on off switch. But it doesn’t! And neither does the other. I’d be really pleased to hear from somebody who could tell me how this set would be operated. Whether the aerial connection was for a long wire feed to the antenna itself. Or simply a fine wire whip the antenna was poked in the hole?

Now the receiver is completely sealed and I’m sure I read somewhere on this forum that this was something to do with making it tamperproof. And if you did manage to tamper with it your guarantee would be void. There are two holes on one of the long sides these are clearly for adjusting core slugs. With a non metallic screwdriver I assume.

Back to the transmitter. Does anyone remember practical wireless magazine and all of those weird and wonderful adverts in the back? I’m absolutely sure there was one particular advert that was for a radio control system that looked just like the Pathfinder with two push buttons on the front. It didn’t bear the Ripmax name tag but otherwise looked very similar. I have a feeling it came under the title “boffin projects “ I remember my mum laughing at this!

This was the first RipMax Pathfinder.
Antenna was a 36" piece of 12g piano wire.
Left hand button was known as the economy button which turns on the valve heater so you would be ready to radiate a signal when the right button was keyed. Both buttons are non latching. I seem to remember that the instructions suggested you stuck a cork on the end of the aerial so you didn't blind your modelling mates.
HT was 90v, LT was 1.5v.
Valve 3V4
Tx was designed to be hand held in operation and never resting on the ground as the capacitance effect would significantly affect the radiated signal.

The rx had a single 3V4 valve. Batteries were again 90 v for the HT and a 1.5 v for the LT.
To open the RX you needed to cut around the glue line under the badge. Rx antenna should be 30".

RX output wire key..

Black - common neg
Orange - LT +ve
Red - HT +ve
White - relay common
Green - N/C
Blue - N/O
Brown - unused

Your Tx is nicer than mine. Mine is missing the gold badge.

Cheers,

Shaun.

SO informative Shaun ! Thank you so much
When I get my battery packs made up I will test it out .
Really good to solve the tx aerial query
Jonathan

Just use multiple 9v PP3'S for the HT.

They don't need to be expensive Duracell types as the demand on them isn't high, but you need to watch out for the very cheap ones from budget shops labelled 9v style battery. These tend to have one cell less and feel lighter. The terminal voltage on these as new will only be around 7.5v. you get what you pay for.

On www.singlechannel.co.uk (in the archive tab file H02) we have selection of 90v battery scans so you could print them out on paper, bond to thin card and make some replica batteries up.

Shaun.

Rather than messing around with making HV batteries from PP3, I use a DC/DC converter designed to supply Nixie tubes, use an old 4S lipo or 12V supply to power it, set it to near the lowest output voltage and away you go, most decent multi-meters can check the output voltage, just remember to use the DC range. It was cheaper to buy than 10x PP3 batteries and when your transmitter collection progress to owning ED and other valve sets, it can do 130V if needed as well. This one is from a different seller, but looks near identical to mine.

https://www.ebay.co.uk/itm/324542267784?

Mike

Probably better and cheaper Mike but it doesn't look as good when using a repro standalone HV battery.

Amazon basics 8 x PP3's £7.50.. they will last year's for a HT source.

Progress to owning ED? .... well I had a massive stroke of luck and very grateful I am to to be the recipient of what could be a Black Knight Tx ? And two receivers all in stonking condition

Maybe Black Knight for Black Magic ?
That ‘battery eliminator’ gadget sounds a good idea - will check that out.

LOVE the battery scans had rummaged around and found those on here earlier.
I remember my RCS being stuffed with two great big uns at the bottom of the case

Hi Jonathan

Great stuff you getting some ED, somewhere I've got the review and circuit diagrams for the ED RCI, but I found the RCM&E review of the Black Knight. And you only need the 130V for the earlier MK1, 2, 3, 4 and Everest floor standing Tx, you don't need such a high voltage for the PCI!

Cheers

Mike