HP B, 3586A manual Measuring Carrier Signal Strength

Page 16

8.MEASURING CARRIER SIGNAL STRENGTH

8.1General - In this chapter we’ll do an example showing the use of the carrier mode in the A and B versions. This mode is not available in the C version but this example can be performed with a C version by using the low distortion selective mode by using the procedure described in chapter 7. If you saved the C models configuration in chapter 7, press [RECALL] followed by entering 1 on the entry sub panel keyboard.

If you have the A or B version, press [CARRIER] on the measurement mode sub panel under SSB channels. The instrument will default to the 20Hz filter but to aid in tuning a carrier you can select a wider filter then return to the narrow filter for the actual level measurement.

Let’s do an example of on the air measurement of the accuracy of our outboard receiver’s signal strength meter that reads in S units of 6db per S unit up to S9, then db’s over that level and is suppose to be calibrated for a 100uv antenna input to give a meter reading of S9.

8.2Normalizing the Measurement – Now let’s calculate a db.775V display offset to reference the display to 100uv or .0001 volts. This will make the display read 0db when the input signal is exactly 100uv, .0001 volts. Calculate the offset using the following formula.

OFFSET = 20 log (Vr/.775) = -77.79db Where the new voltage reference Vr = .0001 volts

Enter the calculated offset into display offset register by pressing [OFFSET] on the entry sub panel, followed by entering the absolute offset number on the entry keyboard of 77.79, then pressing [-db] followed by [MEAS CONT]. Now activate the offset calculation by pressing [OFFSET] on the measurement/entry panel to turn the button’s light on and the O annunciator behind the dbV.775 units.

8.3Measuring the Carrier’s Signal Strength – This is an example of a procedure to measure a signal’s strength in db over or under a normal S9 level of a receiver’s strength meter level calibrated for 100uv signal equal to a S9 reading.

Tune the HP3586 to exactly the carrier frequency of the 40 meter broadcast carrier on our outboard receiver using any of the previous frequency tuning methods. If you initially tuned the carrier using the SSB detector, set the measuring range for 10db and the range upper limit for automatic to be able to hear the signal. Because of possible carrier fading, be sure averaging is on; press [AVE] on the measurement/entry sub panel. Once you have the signal in the filters pass band lock onto it using the counter and transfer it to the frequency register using the methods previously described in chapter 6. Switch back to the 20Hz filter if you used a wider one for tuning the carrier and to the 100db measuring range for less noise error and more stable readings.

The HP3586 should now display db readings close to that of the receiver’s S meter if the S meter is in its db range over S9 and if the reading on the instrument is positive indicating a reading over the 100uv S9 value. For –db and S meter readings below S9, just divide the absolute –db value by 6db and subtract that number from 9 to get the S unit value between 0 and 9. Don’t be surprised if you receivers S meter reading is different than the measurement of the HP-3586

When doing this experiment I found it instructive and fun to also set the measuring range at 100db but set its upper limit for entry and then enter 0db as the limit. However, when I tried to set the limit at 0 it defaulted to +1dbm because of the resolution of this setting wouldn’t allow exactly 0db. But I wanted the analog meter to be close in dbm and 1db won’t make that much difference, it’s close enough for government work. Now the meter was reading signal strength in dbm where the display was reading average db above S9 for signals on an AM net on 75 meters. It was interesting and instructive to see signals between S8 and 25db over S9 on the LED level display were running from –75dbm and up to – 50dbm on the analog meter.

16

Image 16
Contents Version 2.0, September Table of Contents Introduction Description of the HP3586 Page Selective Signal Connections Front Panel Description and Initial SET UP Page Page Setting and Measuring Frequency Page Power Level Measurements Using the Selective Mode Page Voltage Level Measurements Using the Selective Mode Measuring Carrier Signal Strength Tuning SSB Signals Using the Selective Mode Filter Band Width Carrier Offset Tuning a SSB Signal Using the NOISE/DEMODULATION Mode Measuring Audio Noise Using the Wideband Mode Measuring Impulse Noise Measuring Audio Harmonic Distortion Page Passive and Active Network Analysis Page Measuring a TRANSMITTER’S Spurious Emissions Page Selection of Measurement Modes and Other Considerations Page Page Appendix a Understanding the Decibel Ratio Measuring SystemNumber Ratio Power DB Ratio Page HP3586 Error Codes Appendix BSchematics for Useful HP3586 Accessories Appendix C
Related manuals
Manual 258 pages 14.72 Kb Manual 174 pages 33.79 Kb Manual 8 pages 30.64 Kb Manual 88 pages 20 Kb Manual 11 pages 52.74 Kb Manual 122 pages 13.19 Kb

B, 3586A, C specifications

The HP C3586A and C3586B tape drives are notable components in the realm of data storage solutions, primarily designed for enterprise-class environments. These SCSI (Small Computer System Interface) tape drives are regarded for their efficiency, reliability, and capacity to meet the growing demands of data backup and archival processes in businesses.

The C3586A model utilizes the DAT (Digital Audio Tape) technology, which allows it to deliver high performance and high data density. It features a native capacity of 2.3 GB per cartridge, which can be extended to 4.6 GB with the use of compression. This is particularly advantageous for businesses requiring significant amounts of data storage without the necessity for multiple tapes. The transfer rate is rated at up to 12 MB per minute, which ensures quick backups and restores, minimizing the operational downtime.

In terms of data integrity and security, both models incorporate advanced error correction techniques to guarantee that data remains pristine and intact throughout the storage duration. They are designed to work seamlessly with a variety of operating systems and backup applications, enhancing compatibility and user convenience.

The HP C3586B, on the other hand, offers similar foundational technologies but with enhanced features. It supports higher capacity tapes and is engineered to work seamlessly in high-performance environments. With the integration of SCSI-2 interfacing, users can expect faster data transfer rates, which is critical for organizations dealing with large volumes of data.

Another key aspect of both models is their rugged design, which provides durability and reliability needed for long-term storage solutions. The drives are built to withstand extended usage, which makes them a cost-effective choice for businesses looking to invest in dependable data storage systems.

Furthermore, these drives come with a user-friendly interface and straightforward maintenance. This allows IT personnel to handle backups with ease while keeping the workflow uninterrupted.

In summary, the HP C3586A and C3586B tape drives epitomize the union of technology, usability, and dependability. Their robust features, including high data capacity, fast transfer rates, and durable construction, make them a formidable choice for enterprises seeking efficient data backup and archival solutions in the ever-evolving digital landscape.