Seattle Repeater Group Test Functions

The test functions of the Seattle Repeater Group's repeater are initiated with a DTMF (Touchtone ®) "*" (Star) key. The second key struck determines the test from the list below.

In order to use the primary test functions, the DTMF (Touchtone ®) of the radio must be working. This is sometimes problematical since many radios have the DTMF deviation set too high to properly decode on the repeater.

The data used in these test functions (audio deviation, DTMF deviation, frequency, and amplitude) are also recorded for each regular transmission and reported back in the data burst (courtesy tone). If someone is on-line with the data burst decoding capability , they may be able (and willing) to give that data for some users.














DTMF Buddy Test

If a HAM (call sign XXX) has a radio which has a DTMF that is not functioning properly (e.g. its DTMF signals are not decoded by the Seattle Repeater Group's repeater), another HAM (with working DTMF) can assist the first HAM in determining what is wrong by initiating the DTMF Buddy Test. The second HAM (with the working DTMF), keys up the repeater, says "Initiating DTMF Buddy Test for XXX", hits the "*" and then the "1" kys on his DTMF pad, identifies with his call sign, and unkeys. The repeater will say "Seattle Repeater Touchtone Test Ready". The first HAM, XXX, then keys up, says "Testing DTMF", and hits up to 16 keys on his DTMF pad, identifies, and unkeys. The repeater will then list the DTMF keys that it was able to decode. The Repeater then give a voice synthesized message "Touchtone deviation is X.Y KHz" reporting the audio deviation of the DTMF keys that it decoded.

If one key consistently does not decode, it may be bad. If three of four keys consistently do not decode, see if they are in a row or in a column on the keypad. If so, you may have a bad row or column on the keypad. Since a properly adjusted transmitter will use about 3 KHz of deviation for DTMF, if the minimum or maximum is much different than that, a likely explanation is that the DTMF deviation of the radio is set incorrectly and must be adjusted. (It is very typical for a radio's DTMF deviation to be set too high when it is adjusted by many radio shops (including manufacturer's repair facilities.))

If no keys are decoded, you may wish to attempt the (audio) Buddy Test with the second transmission not speaking but simply repeating one key several times. (Note: After the unkeying to end the test, you should key again and identify with your call sign to satisfy FCC rules.) The Audio Report portion of the overall report will then indicate the audio deviation level of that DTMF key. (Note: By not speaking at all, the only audio that will be registered will be the audio level of the (undecoded) DTMF tones.) This level can then be reconciled with the requirements for DTMF tones.










Deviation Test

The user keys up his transmitter, hits the "*" and "2" keys on his DTMF pad, talks (normally) for about ten seconds, identifies with his call sign, and unkeys. The repeater will produce a voice synthesized report listing the minimum and maximum audio deviation detected in the transmission between the release of the "2" key and the unkeying. (Note: for the test to help determine whether the radio is working properly for normal usage, it is important that the microphone he held at the normal distance from the mouth and that the voice level be normal.)

(Note: It is important that the length of the transmission be at least 5 seconds long. Shorter transmissions will give back data that may be incorrect (too low.))

The Repeater then uses a voice synthesizer to report "Peak deviation is X.Y Kilo Hertz."

If the deviation is less than 2 KHz, the operator should consider talking closer to the microphone, talking louder, or adjusting (or having a qualified person adjust) the radio.

If the deviation is greater than 4.5 KHz, the operator should consider talking further away from the microphone, talking softer, or adjusting (or having a qualified person adjust) the radio.














Frequency Test

The user keys up his transmitter, hits the "*" and "3" keys on his DTMF pad, talks for about ten seconds, identifies with his/her call sign, and releases the microphone key. The repeater will then transmit a voice synthesized message "Frequency is XX KiloHertz too high" or "Frequency is XX Kilo Herts too low" or "TBD".

If the frequency error is less than TBD KHz, there is no need to worry. If it is greater than TBD KHz, the operator should seriously consider adusting it (or getting a qualified person to adjust it.)














Amplitude Test

The user keys up his transmitter, hits the "*" and "7" keys on his DTMF pad, talks for about ten seconds, identifies with his/her call sign, and releases the microphone key. The repeater will then transmit a voice synthesized message "Signal Level is minus XXX dBm".














Buddy Test

If someone has a radio without DTMF (or whose DTMF is not functioning properly ), another HAM with DTMF can set up the test for him/her. The procedure is for the DTMF equipped HAM to announce that he is setting up the "Buddy Test", hit the "*" and "0" keys, identify with his call sign and unkey. The repeater will say "Seattle Repeater Radio Check Ready". The other HAM (without working DTMF), now keys up, talks for about ten seconds, identifies with his/her call sign, and unkeys. The repeater will give the report on the second transmission as it does for the Overall Test














Overall Test

The Overall Test combines the functions of the Deviation Test, Frequency Test, and Amplitude Test as well as the report of the DTMF Deviation Test into one single test report on the state of the tested transmitter. The Overall Test is initiated by keying up, hitting the "*" and "#" keys talking (at normal voice level) for about ten seconds, identifying with the call sign and unkeying. After unkeying, the repeater will provide a synthesized voice description of the test results including the Deviation Report, the Amplitude (Signal Strength) Report, the Frequency Report and, if any DTMF keys were decoded, DTMF Deviation Report.














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Created: 1999 May 23 Last Modified: 2002 December 7

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