I have a Pro 1 High Band radio (Will try to get a pic??) that still receives. I do not remember if the light(s) work or not. But it does have slots in the bottom?? for two crystals that can override the dial tuner. Can crystals for this receiver be purchased still?
Realistic Patrolman 3A
- Thread starter K7MFC
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Bumping this this up again with a quick question for anyone who may be able to help. I'm wondering if it is possible to have a single antenna for this radio. There are two old Motorola-style antenna connectors on the rear of this radio, one each for VHF and UHF:
I'm wondering if it is possible to have a single antenna for the radio. There are adapters for Motorola <==> BNC connectors like this:
But I guess I would need some sort of "Y" connector here, with a single BNC terminal for a scanner antenna, and two Motorola connectors for the VHF and UHF antenna inputs at the back of the set. Does something like this exist? Is it technically possible to do this without damaging the radio? Thanks!
I'm wondering if it is possible to have a single antenna for the radio. There are adapters for Motorola <==> BNC connectors like this:
But I guess I would need some sort of "Y" connector here, with a single BNC terminal for a scanner antenna, and two Motorola connectors for the VHF and UHF antenna inputs at the back of the set. Does something like this exist? Is it technically possible to do this without damaging the radio? Thanks!
iMONITOR
Silent Key
BNC FEMALE TO MOTOROLA MALE COAX ADAPTER
https://www.ebay.com/itm/SCAN-18-BN...c+adapters&_from=R40&rt=nc&_trksid=m570.l1313
https://www.ebay.com/itm/SCAN-18-BN...c+adapters&_from=R40&rt=nc&_trksid=m570.l1313
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Yes, that adapter is similar to the image I posted - my question is inquiring if the two Motorola antenna inputs can be connected to a single antenna
with a "Y" adapter like this one I just found:
I'm just wondering if that could potentially damage the radio in any way.
with a "Y" adapter like this one I just found:
I'm just wondering if that could potentially damage the radio in any way.
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It will work just fine. I use one of these on a old pro 2001.Yes, that adapter is similar to the image I posted - my question is inquiring if the two Motorola antenna inputs can be connected to a single antenna
with a "Y" adapter like this one I just found:
I'm just wondering if that could potentially damage the radio in any way.
Good to know, I appreciate the reply!
Archie
Member
Love those pics!!
Thanks for posting those old catalog ads and the pics of this classic monitor...45 years ago, damn, where are the years going???????????
Thanks for posting those old catalog ads and the pics of this classic monitor...45 years ago, damn, where are the years going???????????
Archie
Member
What is the function of the af filter on that pictured radio and what is the difference between the two selectivity settings please? One for UHF and the other for VHF.???
According to the Patrolman 3A owners manual, the AF Filter is "a low pass audio filter to reduce the effects of inherent circuit noise. By reducing the bandwidth of the receiver, the filter emphasizes the desired signal." The selectivity knob is a wide/narrow bandwidth setting. It also helps with tuning the needle right on the frequency you want.
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The Y cable in your photo appears to be a direct wired connection between the two outputs with no intervening circuitry in the cable assembly. Looking at the PRO-3A schematics at the back of the owners manual, the VHF inputs are transformer coupled and the UHF input is a capacitor-inductor network. There should be no damage if the VHF and UHF inputs are shorted together but there may be interaction between the circuits that would degrade reception. Since you already have the Y cable, try it and see how it works.
The PRO-3A is a tunable receiver, not a scanner, so reception is only one band at a time. There are several configurations for the antenna connection that would probably be better than the short circuiting Y cable.
The first option is to use a switch at the antenna and manually set the switch for the band you are tuning. Two position switches for TV antennas are common and would be suitable here if used with the correct connector adapters. There should be negligible signal loss and no interaction between the radio inputs if a switch is used. You do need to remember to set the switch to the correct position for the band you are tuning.
The second option is to use a TV two-way splitter at the antenna and connect the two output splits to the antenna jacks on the radio. Use connector adapters as needed to get everything plugged in. This configuration will have about 3.5dB signal loss at each output. That shouldn't be too significant and there is no switch setting to remember as you change bands on the radio.
A third option is to use one of the old scanner splitter-combiners from the 1970's. Hustler made two models, the 5M5 and the LY-5. Radio Shack's equivalent unit was catalog number 20-191. These splitters contain circuitry inside the box that houses the connectors to split the antenna signal into two or more bands. The attached photos show the circuit inside the 5M5. There is presently an ebay auction active for the LY-5 if you want one.
On a different topic, there was a question about the selectivity setting. It controls the IF bandwidth and it affects all three bands equally. The 5 kHz setting requires precise tuning but will provide the best sensitivity and rejection of adjacent channels.
The PRO-3A is a tunable receiver, not a scanner, so reception is only one band at a time. There are several configurations for the antenna connection that would probably be better than the short circuiting Y cable.
The first option is to use a switch at the antenna and manually set the switch for the band you are tuning. Two position switches for TV antennas are common and would be suitable here if used with the correct connector adapters. There should be negligible signal loss and no interaction between the radio inputs if a switch is used. You do need to remember to set the switch to the correct position for the band you are tuning.
The second option is to use a TV two-way splitter at the antenna and connect the two output splits to the antenna jacks on the radio. Use connector adapters as needed to get everything plugged in. This configuration will have about 3.5dB signal loss at each output. That shouldn't be too significant and there is no switch setting to remember as you change bands on the radio.
A third option is to use one of the old scanner splitter-combiners from the 1970's. Hustler made two models, the 5M5 and the LY-5. Radio Shack's equivalent unit was catalog number 20-191. These splitters contain circuitry inside the box that houses the connectors to split the antenna signal into two or more bands. The attached photos show the circuit inside the 5M5. There is presently an ebay auction active for the LY-5 if you want one.
On a different topic, there was a question about the selectivity setting. It controls the IF bandwidth and it affects all three bands equally. The 5 kHz setting requires precise tuning but will provide the best sensitivity and rejection of adjacent channels.
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Fast1eddie
Member
Ah, the good old days of vuhf radio...No digital silliness, just plug in and net the crystal (at 5 bucks a pop) and park it. Getting bored?? Tune around.
Have several of these and have recapped the power supply. Still more do do, great receivers but they have a tendency to overload.
Have several of these and have recapped the power supply. Still more do do, great receivers but they have a tendency to overload.
Thank you pro92b for all that info! Fortunately I had not purchased any connectors or adapters for the antenna setup at the time of my post on 7-26. I'm doing some research and planning for a new shack in my new house, so I really appreciate you laying down some antenna theory and providing multiple possible solutions with photos. Keeping with the vintange Radio Shack theme, I was able to find an old Realistic VHF/UHF antenna splitter (20-191) on eBay for $3 just now.
If anyone in Arizona is looking for a Realistic Patrolman Pro, I just came across this ad for 3 of them (Pro-1B, Pro-2, Pro-3) that look to be in pretty decent condition for only $75! I would love to snag these but I don't just have the time or space for them at the moment.
https://phoenix.craigslist.org/wvl/ele/d/vintage-realistic-patrolman/6597179902.html
https://phoenix.craigslist.org/wvl/ele/d/vintage-realistic-patrolman/6597179902.html
Engine104
Member since 2005
The one on the top was my first scanner. I remember buying crystals for it at the local Radio Shack and that the LAFD kept changing frequencies (33 Mhz), which made me keep buying crystals. 
radioman2001
Member
Those were one of the first monitor/scanners (Patrolman 3) I bought in 1972 along with the Peterson H/L 44, Patrolman 7, and Patrolman 77. The UHF portion of the Patrolman 3 I always felt was pretty deaf, since I couldn't get Yonkers PD less than 15 mi away, even though they were running 250 watts, and I lived on a pretty tall hill.
When I moved out of my parents house I think I left 2 Lafayette tuneable and 2 channel crystal controlled portable receivers ( don't remember the models). One was LB and the other VHF that had capability of being installed in a car or porta pack, and I will be eventually selling all this equipment as I will be moving to a state with only 800.
When I moved out of my parents house I think I left 2 Lafayette tuneable and 2 channel crystal controlled portable receivers ( don't remember the models). One was LB and the other VHF that had capability of being installed in a car or porta pack, and I will be eventually selling all this equipment as I will be moving to a state with only 800.
Archie
Member
radioman2001
It is possible you could not get Yonkers PD in 1972 because they were using speech inversion with their 10 frequency cross band system according to some buff old timers. But it was a failed system that they scrapped sometime later for the same three UHF's used today...
It is possible you could not get Yonkers PD in 1972 because they were using speech inversion with their 10 frequency cross band system according to some buff old timers. But it was a failed system that they scrapped sometime later for the same three UHF's used today...
radioman2001
Member
They never had a 10 channel system, only 10 sites, and not scrambled in any way. That's a discussion for another thread. I saw that same news article, and best I could tell from the photo which was not good was the tech sitting in front of a what was know at that time as a rat race receiver voter comparator.
In around 1969 they moved from Low Band to a hybrid system of a SP HT200 and Motran mobiles with VHF transmit and UHF receive, and the bases were Motrac 250 watt UHF tube units (monsters that weighed in at around 650 lbs). I actually have one of those units sitting in my shop right now heading to the dump. Along with 3 225 watt Micors heading for the same.
In the late 80's I actually worked on their newer UHF system installed in the early 80's with MT500 portables and Mocom 70 mobiles with Micor 225 watt repeaters located at 3 main 225 watt sites (PS6, North Command,Grassy Sprain), and 2 or 3 additional 110 watt sites which I cannot remember exactly. One was the elementary public school down along the Bronx River Parkway and another was another school East of Central Avenue and Jackson Ave. All the other locations were voting receivers, and believe me they had them hidden in closets and attics of schools all across Yonkers.
I know for sure they were UHF in 1971 as I ran into some buffs at Nathans on Central Ave one summer night and they could only get the mobiles on VHF, because they didn't have a UHF radio. Boy I miss those days.
In around 1969 they moved from Low Band to a hybrid system of a SP HT200 and Motran mobiles with VHF transmit and UHF receive, and the bases were Motrac 250 watt UHF tube units (monsters that weighed in at around 650 lbs). I actually have one of those units sitting in my shop right now heading to the dump. Along with 3 225 watt Micors heading for the same.
In the late 80's I actually worked on their newer UHF system installed in the early 80's with MT500 portables and Mocom 70 mobiles with Micor 225 watt repeaters located at 3 main 225 watt sites (PS6, North Command,Grassy Sprain), and 2 or 3 additional 110 watt sites which I cannot remember exactly. One was the elementary public school down along the Bronx River Parkway and another was another school East of Central Avenue and Jackson Ave. All the other locations were voting receivers, and believe me they had them hidden in closets and attics of schools all across Yonkers.
I know for sure they were UHF in 1971 as I ran into some buffs at Nathans on Central Ave one summer night and they could only get the mobiles on VHF, because they didn't have a UHF radio. Boy I miss those days.
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Archie
Member
radioman2001
According to the 1970 YPD Annual Report, it stated that they were using a 6 channel vhf/uhf cross band system with four UHF's separately assigned only to investigative units and off limits to all others.... I can email you the scanned page if you want, message me with your email address...
According to the 1970 YPD Annual Report, it stated that they were using a 6 channel vhf/uhf cross band system with four UHF's separately assigned only to investigative units and off limits to all others.... I can email you the scanned page if you want, message me with your email address...
radioman2001
Member
I am very familiar with their system, the report gives a indication of a 10 channel system but actually they had 3 VHF channels as inputs to the UHF channels 1-3. The UHF inputs not being used for the repeaters were used for street crime and investigators. When they went pure UHF the VHF inputs were transferred to street crime and investigators. I used to FCC the radios so I do have some first hand knowledge. While the street cops radios were UHF MT500 the street crime units were early Saber I's, and this is in about 1988-90.
I fixed a lot of problems MOT didn't want to so they could sell them the VSELP Astro Saber digital system in 1994-5.
Maybe I will try and do an archival lookup of their freqs.
Can't back before 1996.
I fixed a lot of problems MOT didn't want to so they could sell them the VSELP Astro Saber digital system in 1994-5.
Maybe I will try and do an archival lookup of their freqs.
Can't back before 1996.
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