[Premium-Rx] RACAL HF ACTIVE ANTENNA AE3001/A/C/LP2 WITH DATONG OR WELLBR...

Wed May 6 08:20:04 EDT 2015

Hi Dave

The manual I sent  you was the better copy, I scrapped the old  one:-)

It does sound like you've got a different version to the manual, or  
different revision at least, so if you do trace the main or add on board I'd be  
interested to see the results.

Power interfaces are simple enough, if you do a search on the PA0RDT  
Mini-whip I would think the interface from that would be ok, preferably the  
later one with added fuse and diode rather than just the earlier LC  version.

Watch out for the Wellbrook interface, that one has the negative on the  
inner of the coax, the reverse of most, if not all, others I've seen.

Regards

Nigel
GM8PZR

In a message dated 06/05/2015 12:38:55 GMT Daylight Time,  
premium-rx at mailman.qth.net writes:

Hi, been  away for a bit, many thanks for all your replies, especially for  
the  manual scan, its perfectly useable, no need for a better copy. I  
dismantled  the aerial head unit, until I read the manual, I had no  idea 
it could 
be opened  without destroying it!! It appears to be a  /C model, 1 to 
100MHz, 
backed up by  testing, so I thought it would  be easy enough to convert to 
the more VLF version  by cutting the  link (or links) one for disabling the 
co.ax fed power and the  other  to disable a simple low pass filter, boy 
was I 
wrong! (stop reading now  if  bored!) anyway, to save drilling holes in it 
for 
a power feed  cable, LK2 needs  to stay in place, but there is no LK1 
present,  instead, its a spark gap!, So  theoretically it should work down 
to VLF,  
but test results show it very poor at  MSF, Also inside is a small  PCB 
with 
RACAL on it, so must be factory, and on it  are two small  things that look 
like mini relays, but I think they are variable   attenuators, variable in 
the 
sense of which pins you use determining the  freq.  and/or attenuation. I 
am 
going to try to draw out the circuit  later. While I am  here, does anyone 
have the circuit of the  WELLBROOK loop aerial interface unit,,  or the 
DATONG 
version, I am  going to try and adapt one of these to suit the  RACAL, Dave 

MW1DUJ.

In a message dated 22/04/2015 07:46:34 GMT Daylight  Time,  
premium-rx at mailman.qth.net writes:

Hi   Dave

I wondered where that one went, I quite sulked to have missed  it  at the  
time:-)

Some versions take the supply up the  coax,  some have a separate power 
feed, 
all require +31 volts  DC.
It's a  fairly standard active whip circuit, FET input and bipolar  output, 

in this case though the former is a 2N6660 medium power  MOSFET that  Racal 

insisted had to be the Siliconix  part.

About ten years  ago I scanned the manual for these but  looking at that  
again now I  can see the limitations of the  scanner I was using, probably 
of  
the  bloke doing the  scanning too:-), and am not best impressed with my   
efforts, so  if you can bear with me I'll do it again today and let  you   
have a 
better copy   later.

Regards

Nigel
GM8PZR

In a message  dated  22/04/2015 02:19:19 GMT Daylight Time,   
premium-rx at mailman.qth.net  writes:

Hi, I  have recently  acquired one of these fine looking  beasts, a black   

plastic blob with a lovely water shield/ground  plane, and about 1M  whip  
attached  to the top, the only thing  is that it came  with no  paperwork 
or 
interface 
necessary to  power the  aerial. Presumably, one  sends the supply voltage 
up   
the  CO-AX aerial feed, like the  interfaces popular with   Wellbrook, 
Datong 
etc, and I  am sure that if  I looked that  I  could find one of these, but 
the 
question is,  what   is the  voltage that needs to go up the CO-AX? Has 
anyone 
got any  ideas,   or  better yet, racal paperwork for it? Maybe its  
standard 
12V,  if  so, I might try  it with my JRC receiver  which has a switched 12 

volt  
supply which can be   switched in or out of the aerial  feed, any help  
much  
appreciated, Dave.     MW1DUJ.
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______________________________________________________________
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