RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > HF / MW / LW Monitoring > HF/MW/LW Equipment


HF/MW/LW Equipment - For general and technical discussion of all receivers which cover the HF bands. For HF tranceiver discussion please use the Amateur Radio Equipment forum above.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 01-09-2018, 7:36 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Feb 2014
Location: Western NJ
Posts: 323
Default Frequency Selective Voltmeters as Receivers

Saw a comment on this forum about frequency selective voltmeters, did some data mining on the 'Net and it appears these were old commercially-manufactured units used by power companies. Perhaps there are some folks on this forum who used these on the job.

Anyway, some of these units cover LF, MW, and some even cover up to 9 megs AM/SSB. Given, they're not designed for LF/MW/SW hobbyists but wondering how they would fare as LF/MW receivers. I'd imagine these must have cost a fortune back in the olden days.

Thanks for any comments.
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 01-09-2018, 8:19 AM
Member
   
Join Date: Feb 2007
Location: 175 DME, HEC 358 Radial
Posts: 5,512
Default

They're basically precision calibrated SSB receivers. Frequency coverage is from 0 to anywhere up to 30 MHz depending on the make and model. They can make excellent VLF receivers, but typically don't have amenities like noise blankers. They were used to set levels on analog FDM mux.

I would expect a preamp to be necessary. The receive threshold is somewhere around -70 dbm.

I paid about $10k a piece back in the 80's.

Last edited by zz0468; 01-09-2018 at 8:25 AM..
Reply With Quote
  #3 (permalink)  
Old 01-09-2018, 11:30 AM
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Aug 2008
Location: Oregon Coast
Posts: 102
Default Selective voltmeters...

The HP 3586 series are awesome units; I recommend the 3586C if you're going to go looking for one. They measure frequency to fractional Hz, levels to fractional dB, and actually provide an RF output exactly what is displayed on the receive frequency window. VLF to above the top end of HF. About 90 pounds of 1980's technology.

No AM reception except by zero-beating the AM carrier in SSB mode, and there isn't a big variety of filter bandwidths. I don't find it a big deal, I'm not looking for high fidelity. They aren't a general-coverage receiver but have many uses for off-air evaluation of signals.
__________________
Q: "Why jump out of an airplane?"
A: "Because the doors open!"
Reply With Quote
  #4 (permalink)  
Old 01-09-2018, 1:20 PM
majoco's Avatar
Member
  Shack Photos
Shack photos
 
Join Date: Dec 2008
Location: New Zealand
Posts: 2,757
Default

I bought an HP3586A in a not-fully-operational mode for a pittance and fortunately found the major fault quite quickly - someone had replaced a screw for the handle that was far too long which bit into the front panel printed circuit board shorting one of the 5volt supply rails to ground which overloaded and overheated the power supply - fortunately it survived! Other minor things were easily dealt with and now I have a magic piece of gear that I use for all sorts of things. The audio output on the rear panel is very good, filters are good of course and the frequency accuracy and stability are excellent. It will lock on to any carrier above a couple of microvolts and show its frequency down to 0.1Hz! - and as a bonus will radiate a carrier to the same accuracy! You'll have to get your head around working with dBm's instead of uV - mine goes down to -120dBm which is around 0.25uV in 50 ohms. It's an engineering marvel inside too - the 2-volume manual is online and a couple of guides to get you started. Here's mine displaying our local AM band station....
Attached Images
 
__________________
Cheers - Martin ZL2MC - Palmerston North

Last edited by majoco; 06-17-2018 at 7:29 PM..
Reply With Quote
  #5 (permalink)  
Old 01-09-2018, 1:48 PM
mmckenna's Avatar
Member
   
Join Date: Jul 2005
Location: WTVLCA01DS0
Posts: 8,995
Default

I picked up a Rycom unit off e-bay a year or so ago.
Battery powered, runs off an internal 12 volt rechargeable battery. I replaced that with a new one.
Weighs about 7 pounds.

Receiver works well. I haven't felt the need for a preamp, but it would be interesting to try.

The Rycom is a basic unit, designed for field portability.

I think I paid $45 - 50 bucks for mine. Put a new $20 12 volt battery in it, charged it up, cleaned the case and it works fine.

I built a loop antenna with PVC pipe and that seems to be a good combination. Picked up Aero/NDB long wave beacons fairly well. Pulled in a few DX AM stations, well, too. Issue though, at least with mine, is the IF width is not ideal for AM listening. In other words, not a radio you are going to want to listen to music on, but great as a receiver for chasing down signals.

There's usually a few on e-Bay at any given time. I think mine had a calibration sticker on it from the mid 1990's.
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 01-09-2018, 2:08 PM
northzone's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Dec 2002
Location: Northern California
Posts: 812
Default

I had both a Sierra and a Rycom for my work with analog microwave. The indivual channel cards actually modulated SSB. Then groups of channels were mixed together to modulate the microwave baseband (70 mhz) with an FM signal.

We once put in a system that had 90 voting receivers with constant status tone. This caused the baseband to go into a Bessel Null and we lost all baseband.

Fun stuff.
Reply With Quote
  #7 (permalink)  
Old 01-09-2018, 8:34 PM
jimvm's Avatar
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Feb 2005
Location: Olivehurst, California
Posts: 214
Default Frequency selective voltmeter

I used a Sierra 303B for years. Sold it for $40.00.

jim vm
Reply With Quote
  #8 (permalink)  
Old 01-10-2018, 5:37 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Feb 2014
Location: Western NJ
Posts: 323
Default

Thanks for the comments, much appreciated.

I found a Sierra 303B and am awaiting it's arrival.
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 8:55 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions