Batboard

Hello all! I want to start off by saying I'm not a professional and only do this as a hobby. I've used this board a number of times the past couple of years and find it to be a well of information. What I have is a general question about Saber/Sys Saber alignment. I couldn't find any info on this particular question.

I know I can upgrade the band split on a uhf from the dreaded gov band to the 440-470 band by swapping the modules. As a matter of fact I have done this twice so far with good results. I know it is recommended to do an alignment after such a swap to make sure everything is still in spec.

My question is this. Is the alignment required because each main board is different? If I swap modules from one 440-470 into another 440-470 radio would it still need to be re-aligned or is it because each module is different and the boards the same?

Just curious, thanks for any light you can shed on the subject.

AEC is the one for this, but I seem to remember if you read all the alignment points in the radio the modules come from and write them down. You can put these alignment points into the "new" radio.

Other wise you need a service monitor, the Saber service cable, and the RSS to do a proper alignment.

AEC does the Saber repairs for our ERT. I stick to the Spectras, Jedi radios.....

Thanks for the reply. Following this logic the modules are the variable and the main boards all the same (UHF). Sorry if this was a stupid question.

That is a prety close asumption. The reason they have the alignment points is to match different variables in the modules so the modulation is correct, as in the VCO and TX audio modules. Also the radio sets 'tuning' points depending on which section of the band the radio's channel selector is on. These tuning points set the alignment for the RX front end, the TX modulation compensation, deviation gain and TX power output control for that paticular frequency.


On the Saber, the alignment 'points' are set for each channel. It does take a calibrated signal generator for the RX, and a deviation scope (service monitor has all this in "one box") to set the TX deviation, TX dev compensation (ratio of low frequency ie; PL or DPL, and voice deviation).

One nice benifit is you can set a channel for narrow +- 2.5k TX deviation, low TX power, ect;..

Thanks Will, That was exactly the info I was looking for. Now I have one last question that will show my inexperience. In the saber line does the frequency drift over time? Do you periodically have to re-align the radio to stay in spec? If so how often? I always assumed once it was aligned it stayed there. You know what they say about assuming!

Thanks once again!

I maintain around 2500 Sabers for my city. With the exception of a defective reference osc, I rarely have to reset the frequency.

Most good crystals do most of the drifting when they are young. Sabers are well past that!

Reference oscillators rarely 'drift' as the radio has specific controls that adjust the 'warp' of the reference oscillator over time, and readjusts this 'setpoint' several times during operation, especially if the radio is used extensively outside, then inside for extended periods, this will cause the ref. osc. to 'recalibrate' according to ambient temeratures, and happens automatically as well, so no operator intervention is necessary.

The compensation occurs rapidly and changes often, or not at all, again, depending on temperature.

You can adjust this point within the RSS service menu, but after adjustment, the frequency counter will show the exact freq. it's currently resting on, then later in the day, the temperature changes will cause the setpoint to readjust for the differing temp and the set point is no longer valid, but will remain at the point you set it within the RSS, but does not 'lock' the reference osc. at that point, it will shift up or down with temperature.

It's a continuously adjusted setting, the 'baseline' point is RSS set, the actual setting is handled exclusively by the radio.