Modifications for the Radio Shack PRO 51

Transcription

1 Modifications for the Radio Shack PRO 51 Picture(s) of Radio Shack PRO Cellular on the "blocked" PRO 51 English language Expanded coverage on the Realistic PRO 51 and PRO 23 English language PRO 51 Mod: Shorten squelch tail English language Cellular on the "blocked" PRO 51 Forward messagge There is an interesting test mode in the PRO 51 that, combined with the direct search feature of the scanner, lets you pick up out of band frequencies. You will have full access to the Mhz ranges as well as the cellular base range of Mhz. Actually, there are several test modes in the PRO 51 (most of these comments should be true for any Uniden made Radio Shack scanner, such as the PRO 46). I'll describe them first and then how to take advantage of one of them to get the restricted frequencies. There are three data test modes. These modes completely destroy any frequencies you had programmed into your scanner, so it's best to use these techniques before you program your scanner. If you have already programmed it, you'll have to decide if these new capabilities are worth reprogramming. Test mode 0. Clear the scanner. A well known method of clearing the scanner to all zeros is to hold down the 2 key, the 9 key, and turn on the scanner. All frequencies will be lost. TEST MODE 1. Fill channels 1 25 with test frequencies. Press the 2 key, the 9 key, the L/Out key, and turn on the scanner. This fills channels 1 25 with these frequencies: radio=radio_shack&model=pro 51&selectid=all.htm 1/6

2 * * * * * indicates not within the PRO 51's normal coverage. More on how to use these in a minute. TEST MODE 2. Fill channels 1 17 with test frequencies. Press 2, 9, Manual Fills channels 1 17 with these frequencies: 30.00, 40.00, 50.00, , , , , , , 54.00, , , , , , , There is also a display diagnostic mode. Display Test Mode. Press 2, 9, Band or 2, 9, Moni. This put the display in test mode. Every annunciator and every digit element is turned on in a scan from the left side of the display to the right. To keep this test mode continuous, release the buttons before the first scan finishes. This mode does not affect stored memory. Press any key to exit this display mode. Now, if you've decided to try test mode 1, you will find several out of band frequencies stored in your memory channels. Channels hold frequencies in the blocked out Mhz range, and channel 23 holds a frequency in the blocked out cellular base range. Once you have these frequencies stored in a memory channel, the PRO 51's direct search feature will let you search though these ranges. In the cellular band, the scanner searches in the correct 30 Khz steps. You don't have to keep these frequencies in these channels. You can move them to any channel in the scanner. First move them to a monitor channel. While on a channel with one of these frequencies, open squelch completely. Press direct search button, either up or down. The direct search button puts the scanner into search mode and the open squelch holds the frequency. Then press the Monitor button. The frequency is now in the monitor channel indicated in the display. Now you can move it to any regular memory channel in the scanner. Enter the channel number radio=radio_shack&model=pro 51&selectid=all.htm 2/6

3 Press PROG Press Monitor Press the number of the monitor channel if the proper channel is not displayed Press E(nter) The frequency is now permanently stored in the memory channel. You can do a direct search from this memory channel at any time. The Mhz range mainly covers TV audio. However, there is a strange phenomenon concerning TV audio and the PRO 51. Channels 4, 5, and 6 audio fall within the Mhz range, yet the PRO 51 will not pick up the audio frequency while searching in this range. However, TV channel 2 audio is at Mhz. When you add the intermediate frequency of 21.6 Mhz, you get an image of the TV channel 2 audio appearing at Mhz. This does come in, although raspy, since the PRO 51 is receiving in narrow FM mode while TV audio requires wide band FM mode for proper reception. I'd be interested in anyone can verify that any of these test modes work on the PRO 46 or any other Uniden made Radio Shack scanner. The test modes I've described as modes 0 and 1 (clearing all channels and plugging in test freqs in the first 20 channels) have been around since the BC200XLT (I think also the BC100XLT). They also appear in the BC2500XLT, although I couldn't find any other test modes in that scanner. The BC220XLT allows you to do a display element test mode, but, unlike Jeff, I haven't confirmed any other modes as I don't want to wipe out all my channels. I expect that Uniden made Radio Shack scanners will have at least these two modes and may have the other modes as well. I'm hoping a PRO 46 owner will test this for us. I wish I could take the credit for coming up with this trick, although it's ironic that I had all of the relevant info in my head...i just didn't put it together. The basis for this trick came from Glenn Cohen of Scanners Unlimited who was told this by someone who walked into his store. Glenn confirmed it with Larry Van Horn at Monitoring Times. I independently discovered modes 3 and 4, which, to my knowledge, have never been published before. I did find the display test mode works on the BC220XLT but didn't want to lose all my memories to try the others. Thanks for biting the bullet and seeing what happens on yours! Of course, without the RS direct search feature, the test freqs in the Uniden label scanners don't do much good. Update Notice Apparently, as a result of this document and publication elsewhere of this test mode, the FCC demanded that Radio Shack pull all existing PRO 51s, PRO 23s, and PRO 46s off their shelves and were forbidden to continue to sell them. This is particularly puzzling, since all three of these scanners could always receive cellular via images without any special modes or procedures. At the end of October 1994, PRO 51s started reappearing in Radio Shack stores (date code of 7A4). These units were apparently shipped to Uniden to have the cellular frequency that appears in test mode 1 (channel 23) removed. If you follow the procedure for test mode 1 on the new PRO 51s, you'll instead get the frequencies from test mode 2, which will not allow you out of band reception. However, Uniden apparently didn't spend much time with this interim modification because it is still radio=radio_shack&model=pro 51&selectid=all.htm 3/6

4 possible to put the "new" PRO 51s into test mode 1. Here is the procedure: First initialize test mode 3 (the display test). While the display is being updated, hold down the 2, 9, and L/Out keys. Keep holding them until the display finishes filling up. It will stop with all of the test frequencies for test mode 1 loaded in memory! Unfortunately, PRO 51s with a date code of 8A4 (August 1994) or later will be able to do all the test sequencies with the exception that channel 23 will not contain a frequency in the cellular range. The other out of band frequencies will still be there. This modification is read 813 times. top of page Expanded coverage on the Realistic PRO 51 and PRO 23 I recently bought a PRO 51 as a gift for a good friend. I asked the manager about mods for the scanner and what follows is the information he gave me. Manufactured by Uniden for Radio Shack, the new Realistic PRO 51 and PRO 23 scanners have cellular frequencies blocked at the factory, but they are easily accessed by a short keyboard routine. 1. With the radio switched off, hold down the 2, 9 and LOCK OUT keys; turn the radio on and release the keys. 2. Step to channel 23 on the PRO 51 or channel 15 on the PRO 23 to display MHz a factory test freuency. 3. Press either the up or down seach arrow to scan the cellular band in proper 30 KHz steps. You may temporarily store up to 10 active cellular frequencies by pressing MONITOR To Permanently store cellular fequencies for scanning and to have a starting point for searches 1. Step to the MONITOR channel you wish to permantly store, then press PROGRAM, then the desired memory channel number (including those with factory preprogrammed test frequencies). 2. Press in sequence PROGRAM, MONITOR, ENTER. Repeat steps 1 and 2 for each channel to be memorized. Although I haven't given the scanner to my friend yet, I'm sure he will be impressed with its sensitivity, programming ease and wide frequency coverage, I sure am! This modification is read 1379 times. top of page radio=radio_shack&model=pro 51&selectid=all.htm 4/6

5 PRO 51 Mod: Shorten squelch tail This change was performed successfully on a unit coded "11A3." The CPU in this unit was marked "Uniden UC1581." Use the following information at your own risk! Neither I nor my employer are responsible for any damages you may incur from this information! Orientations are with the set flat on a work surface, LCD display facing down, with antenna BNC and knobs facing away from yourself. As with any electronic instrumentation, remove all power and take all necessary precautions to prevent damage from electrostatic discharge (ESD). This modification requires fine soldering and familiarity with surface mount devices. CAUTION: Be aware that parts of the circuitry will *still* be powered! There is a capacitor on the digital board that keeps the channel memory alive. This capacitor may contain enough energy to damage the electronics should a short occur. Parts required: One 1/10th watt carbon resistor, 100K to 220K. Value is not critical. A lower value shortens the time the squelch remains open after incoming signal stops. The resistor should physically as small as possible. Opening Case Fortunately, this set is very easy to open. Open battery compartment and remove batteries. Remove four screws: two straddle the sticker on the back of the cabinet, two others at the upper part of the battery compartment. There are two small plastic detents at the floor of the battery compartment. They are directly downwards from the " " and "+" legends, which are molded on an extension of the removable back. These detents will need to be unhitched to allow the back to separate from the front. Pull back off gently. Remove RF board The RF board is attached to the top panel, which contains the volume and squelch controls and the antenna connector. At this point, the board is essentially free and will separate from the rest of the set when the header connector at the lower right is pulled apart. This header provides electrical connections between the two boards. Lift the RF board straight out, and set the rest of the radio aside. Flip RF board over, keeping BNC pointing away from yourself. Add resistor Refer to the ASCII diagram below. Bend one of the resistor leads close to the body of the resistor so that the resistor forms a hairpin shape. Trim leads and solder the new resistor in parallel with the chip resistor marked "105." The latter is positioned between the two surface mount IC's towards the bottom of the RF board. Press the new resistor parallel to the circuit board, making sure there are no shorts. + + [101] radio=radio_shack&model=pro 51&selectid=all.htm 5/6

6 [684] NJM2090V [224] + + [ ] [ ] [ ] [225] [105] [123] + + R < add resistor: 100K 220K + + \_/ + + TK11900M + + Thanks to Bob Parnass for clarifying the nature of the "squelch tail" problem and for inspiring me to figure out this modification. Moy Wong (moy@xp.psych.nyu.edu) Dept. of Psychology, New York University This modification is read 1785 times. top of page Have you any tips, trick or modifications you can't find here, please E mail them to me, or use the mail form. Can't you find a mods, please don't e mail to me. All mods i have is listed on this site.! Back to start page radio=radio_shack&model=pro 51&selectid=all.htm 6/6