Regular readers will know that we love our dividends at Simply Wall St, which is why it's exciting to see GTN Limited (ASX:GTN) is about to trade ex-dividend in the next 3 days. Investors can purchase shares before the 5th of September in order to be eligible for this dividend, which will be paid on the 30th of September.

GTN's upcoming dividend is AU$0.032 a share, following on from the last 12 months, when the company distributed a total of AU$0.064 per share to shareholders. Calculating the last year's worth of payments shows that GTN has a trailing yield of 7.4% on the current share price of A$0.87. If you buy this business for its dividend, you should have an idea of whether GTN's dividend is reliable and sustainable. We need to see whether the dividend is covered by earnings and if it's growing.

Check out our latest analysis for GTN

Dividends are typically paid from company earnings. If a company pays more in dividends than it earned in profit, then the dividend could be unsustainable. GTN paid out a comfortable 34% of its profit last year. A useful secondary check can be to evaluate whether GTN generated enough free cash flow to afford its dividend. It paid out 102% of its free cash flow in the form of dividends last year, which is outside the comfort zone for most businesses. Cash flows are usually much more volatile than earnings, so this could be a temporary effect - but we'd generally want look more closely here.

While GTN's dividends were covered by the company's reported profits, cash is somewhat more important, so it's not great to see that the company didn't generate enough cash to pay its dividend. Were this to happen repeatedly, this would be a risk to GTN's ability to maintain its dividend.

Click here to see the company's payout ratio, plus analyst estimates of its future dividends.

Have Earnings And Dividends Been Growing?

Companies with consistently growing earnings per share generally make the best dividend stocks, as they usually find it easier to grow dividends per share. If earnings decline and the company is forced to cut its dividend, investors could watch the value of their investment go up in smoke. It's encouraging to see GTN has grown its earnings rapidly, up 57% a year for the past five years. Earnings have been growing quickly, but we're concerned dividend payments consumed most of the company's cash flow over the past year.

The main way most investors will assess a company's dividend prospects is by checking the historical rate of dividend growth. GTN's dividend payments per share have declined at 17% per year on average over the past 3 years, which is uninspiring. It's unusual to see earnings per share increasing at the same time as dividends per share have been in decline. We'd hope it's because the company is reinvesting heavily in its business, but it could also suggest business is lumpy.