Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: VHF-LO band on 70s radio?  (Read 883 times)
KJ6ZOL
Member

Posts: 631




Ignore
« on: May 21, 2016, 02:28:56 PM »

I was poking around a local thrift store and found a "Patrolman-4" RS radio from the mid-70s. It has four bands, AM, FM, "VHF-HI" which covers 136-174 Mhz which was the old public service band, and then it has a "VHF-LO" that covers 30-50 Mhz. I simply have no clue what services could be found in the 30-50 Mhz area 40 years ago. Help?
Logged
AA4PB
Member

Posts: 13768




Ignore
« Reply #1 on: May 21, 2016, 02:40:59 PM »

Many state police vehicles used FM on the VHF low band in the early days. It gave better coverage than the VHF high band.
Logged
N3HFS
Member

Posts: 357




Ignore
« Reply #2 on: May 21, 2016, 02:42:13 PM »

Plenty!

Fire and police dispatch were routinely on low band.  State Police and county sheriffs could often cover great swaths of a large state with their mobile transceivers.  Troopers' police cars of that era always seemed to have that super long whip mounted on their rear bumper and tied down to their front quarter panel in a really long arch (ref: The Andy Griffith Show).

Back when there were very few radio system towers (nothing like our current forest of cell and trunking site towers), they made 'em big, tall, and powerful.  Low band VHF was fantastic at covering those wide open spaces (at least most of the time, when there was no skip).  

Car 54, Where are you?!!
« Last Edit: May 21, 2016, 02:54:12 PM by N3HFS » Logged
K0OD
Member

Posts: 2764




Ignore
« Reply #3 on: May 21, 2016, 03:03:23 PM »

I simply have no clue what services could be found in the 30-50 Mhz area 40 years ago. Help?

What's in that range now? I can't think of anything.
Logged
KAPT4560
Member

Posts: 188




Ignore
« Reply #4 on: May 22, 2016, 02:39:28 AM »

 Older cordless phones in the 1980's used 46/49 mc, but you could only hear half the conversation. The handset used another frequency (1700 kc?).
 I was able to pick up wireless intercom/baby monitors in my neighborhood a couple of years ago in this band.
VHF-Lo would have had fair coverage in hilly areas where VHF-Hi/UHF (line-of-sight) may have been undependable.
Public safety has since moved off into the higher frequencies and many around here are now P25 digital format. VHF-TV audio has also moved. You might find some interesting FM images on this band but as stated, not much may be on VHF-Lo now.
Logged
K0OD
Member

Posts: 2764




Ignore
« Reply #5 on: May 22, 2016, 05:55:25 AM »

Older cordless phones in the 1980's used 46/49 mc, but you could only hear half the conversation. The handset used another frequency (1700 kc?).

Yep, just above the AM BCB.

I lived in an 18th floor apartment around 1980. Picking up cordless phone conversations on my TS-430 was easy with a ham mobile whip on the balcony. Only rarely did I know who I was listening to, but once I heard a guy waiting for a table in a restaurant about a mile away... my best DX of that sort.   
Logged
K9RZZ
Member

Posts: 18




Ignore
« Reply #6 on: May 22, 2016, 01:23:32 PM »

There still is activity in that range. I've heard some east coast fire department activity myself from here in Wisconsin. Check out these logs: http://forums.radioreference.com/skip-tropospheric-ducting-forum/328109-2016-vhf-low-band-logs.html
Logged
WA8ZTZ
Member

Posts: 101




Ignore
« Reply #7 on: May 22, 2016, 04:47:10 PM »

Remembering back to my land mobile repair days in the 70s, trucking and construction companies that coverd wide areas used VHF-LO back then.  Usually very tall base towers and 100 watt rigs in the trucks were common. The Motorola MOTRAC VHF LO radios had a feature called an "extender" that was not found in the VHF HI and UHF radios...  IIRC it was a noise blanker as the VHF LO freqs are more susceptible to static than the higher freqs.   Nowadays not nearly as much activity with the consolidation of the trucking business and use of cell phones.
Logged
KJ6ZOL
Member

Posts: 631




Ignore
« Reply #8 on: May 22, 2016, 06:20:45 PM »

Remembering back to my land mobile repair days in the 70s, trucking and construction companies that coverd wide areas used VHF-LO back then.  Usually very tall base towers and 100 watt rigs in the trucks were common. The Motorola MOTRAC VHF LO radios had a feature called an "extender" that was not found in the VHF HI and UHF radios...  IIRC it was a noise blanker as the VHF LO freqs are more susceptible to static than the higher freqs.   Nowadays not nearly as much activity with the consolidation of the trucking business and use of cell phones.

100 watts? Did they need a license for that level of power? It seems to me that under Part 15 rules that they would need a license for 100 watts, one for each rig op. I was born in 1974 so I have no clue about that era. The radio I mentioned was apparently made in the fall of 1975, likely for the Christmas sale season. I finally decided not to buy it, but I did get a good look at it. It was made in Japan, likely by GRE which made a lot of RS equipment in the 70s.
Logged
AA4PB
Member

Posts: 13768




Ignore
« Reply #9 on: May 22, 2016, 07:24:09 PM »

Yes, you needed a license for those radios but the license was issued to the company that owned them. You didn't need an operator's license in order to operate them as you were an employee of the company. 100W was not uncommon, even for the high band VHF radios. The company had to have the radios serviced on a regular basis by someone with at least a second class radiotelephone license issue by the FCC.


Logged
RENTON481
Member

Posts: 127




Ignore
« Reply #10 on: Yesterday at 03:55:32 PM »

I've heard VHF Low Band skip on a Realistic Patrolman SW60, running it through a CB Quad Loop. That was a few years ago, though, when conditions were hot.

From some of the logs I've seen online there still is plenty to hear on that band. I heard what sounded like oil workers in Louisiana and Texas -- the accents and convos gave it away.
Logged
KJ6ZOL
Member

Posts: 631




Ignore
« Reply #11 on: Yesterday at 06:26:46 PM »

I've heard VHF Low Band skip on a Realistic Patrolman SW60, running it through a CB Quad Loop. That was a few years ago, though, when conditions were hot.

From some of the logs I've seen online there still is plenty to hear on that band. I heard what sounded like oil workers in Louisiana and Texas -- the accents and convos gave it away.

I had a SW60 when I was a teen. Never heard much on it though, and got rid of it maybe 12 years ago. I gave it to a thrift store, and a couple weeks later somebody posts (not here, this was back in the usenet era) that he found this Patrolman SW60 in a Sacramento thrift store-the same one I gave mine to-and was raving about what great condition it was in. Finally I realized that he was talking about my old radio-the same one I got rid of because it was just taking up space. So, it at least got a good home.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!