RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Topic Specific Forums > Antennas and Associated Hardware > Scanner / Receiver Antennas

Scanner / Receiver Antennas For discussion of any type of receiving antenna used by a scanner or receiver base, mobile or handheld.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 07-06-2012, 2:09 AM
jaded's Avatar
Member
  Audio Feed Provider
Audio Feed Provider
 
Join Date: Jun 2004
Location: Columbus, OH
Posts: 43
Default Diamond D-707: Amp Needed?

Hi Folks,

I was recently given a Diamond D-707 antenna, but without any pieces but the antenna itself (i.e. no external components). It's an older unit, so I'm having trouble finding specs for this model. A label on the antenna mentions a "Built-in RF Hybrid IC Amplifier", but I'm not sure if this was built-in to the internals of the antenna, and thus requires a proprietary power injector or something like that, or if it was completely external to the antenna. Does anyone happen to remember if this antenna is able to be used on it's own, or am I going to have to crack it open and remove some circuitry in the antenna?

Thanks for your help!
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 07-06-2012, 2:51 AM
n5ims's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2004
Posts: 2,948
Default

This http://www.thiecom.com/ftp/diamond/dserie/d505.pdf makes it appear that the amp was external to the antenna (I don't read the language so it's kinda of hard to tell for sure). Pic 5 shows the amp being external and Pic 4 appears to show the antenna being used without the amp so you may be able to have some success.

Last edited by n5ims; 07-06-2012 at 2:55 AM..
Reply With Quote
  #3 (permalink)  
Old 07-06-2012, 6:35 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2007
Location: NW Ohio
Posts: 1,345
Default

Like N5IMS, I don't read the language but the drawings show an external box with what appears to be an input and an output. You can't really tell from the pictures, it might be the amp or a power injector. I'm inclined to think that it is a power injector. You could try it without the box to see if you pickup anything, it should be pretty deaf if the amp is unpowered and internal to the antenna.

The power injector will be just a DC blocking capacitor between the output connector and the power input jack. It serves to keep the DC power out of the scanner input. The value of the capacitor isn't critical, a .001 fd cap should do the trick. There also appears to be some type of voltage divider to vary the voltage to the amp. The gain of the amp is dependent on the voltage and the low end will be at whatever voltage the amp needs to just offset the internal losses of the amp and I have no idea what that might be.

Good luck.
Reply With Quote
  #4 (permalink)  
Old 07-06-2012, 7:50 AM
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Jun 2006
Posts: 3,576
Default

There is more to a power injector than just a blocking capacitor, there also has to be a series inductor for the power of a value that isolates the power supply side from the RF. For typical scanner use a 5 hole ferrite bead, #43 material with 3 turns is usually good.

You could also use the cheap power injector and wall wart power supply for a TV preamp.
prcguy
Reply With Quote
  #5 (permalink)  
Old 07-06-2012, 12:15 PM
n5ims's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2004
Posts: 2,948
Default

If you look closely at picture 5 you'll see the antenna connecting to an external box (apparently the amp) using the left connector on the amp. The center connector on the amp appears to connect to the power since the plug is by what appears to be an electrical outlet. The right connector on the amp appears to go to the radio.

If you look at picture 4, the antenna connects directly to the radio and the fellow listening is quite happy. This may indicate that the external amp box is optional (or simply that the drawing doesn't show them since they appear to be talking about waterproofing the install, who knows.)
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 07-06-2012, 5:23 PM
mule1075's Avatar
Member
   
Join Date: Jan 2003
Location: Washington Pa
Posts: 1,136
Default

i have one sitting here as we speak worked well or i should say very well for me your results might and more than likely will vary from mine.Now what has been posted i hate to say it guys but do you have on in service it might not work in your neck of the woods but it works well here.Still have mine taking up some space but it is a good antenna for my needs if need be.Just a thought no more no less/.Will be up on the tower sunday going to give the Scantenna i just bought Another Chance.Search here for some threads on here about the d707 it did it work for me yes your results and location it might not work for you.Hope that helps.Adam
__________________
Uniden 125at/ 200xlt/250d/9000xlt/780xlt/796d/996t/346xt/2x396xt/996xt/HP-1E
Radio Shack Pro-2006/160/197.AOR 8200MK3
http://washpascan.no-ip.biz:8001/ My Live Feed

Last edited by mule1075; 07-06-2012 at 5:37 PM..
Reply With Quote
  #7 (permalink)  
Old 07-06-2012, 10:28 PM
jaded's Avatar
Member
  Audio Feed Provider
Audio Feed Provider
 
Join Date: Jun 2004
Location: Columbus, OH
Posts: 43
Default

Thanks for all the replies, folks. I suppose hooking it up and seeing if it works w/o the external mystery box will be step one. Second, maybe I can get the spec sheet N5IMS linked to translated. Lastly, I can always try to open it up and see if there's any active circuitry in there.

Thanks again!
Reply With Quote
  #8 (permalink)  
Old 08-03-2012, 11:31 AM
Member
   
Join Date: Aug 2012
Posts: 1
Default diamond D-707 Instructions in English

http://www.cbshop.nl/pdf/diamond_707...20brochure.pdf
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 8:07 AM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2011 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions