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

[Chuck Urmson]

Hi Dave,

You have the version of the AE3001 that has been modified for Nuclear
Electromagnetic Pulse (NEMP) protection.  If you remember there was a
man called Saddam Hussein who, it was claimed at the time, had WMD.  So
I guess Racal and everybody else had to play along with the myth and
modify their kit before it could be shipped off to Iraq. 

While the non-EMP version of the antenna does work at 13.8V I would
recommend that you supply the 31V as specified to maximize performance
especially IMD.  I also can't remember what the relay voltages are so
that may also present a problem with your version.

I will email my hand-drawn version of the schematic to you separately. 
If anyone else would like a copy or has a site where I can post the
schematic please let me know. 

Regards,
Chuck EA8DBU/M1DPD


 If you give me six lines written by the hand of the most honest of men, I will find something in them which will hang him.
Cardinal Richelieu

On 06/05/2015 12:37, Dave Jones via Premium-Rx wrote:
> 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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