However there is an in-between, the Zulu signal:
It costs 8 gold pieces and gives +20% credits. Ergo, if you earn more than 60K base credits (earning less needs some special kind of fail over tier 5), you earn more than 1500 credits/gold by flying this signal. Sure, it slowly depletes your gold stockpile, which is less than funny. However if you play 4 games per hour, then you paid only 24 gold or less than 10 cents for an hour of entertainment which isn’t much to ask.
In return, you get surprising amount of credits on the long run, because of how the services work on the higher tiers. You get lot of credits, but you also spend the lot, making your net gain small. This makes the small looking 20% closer to 100% net increase.
Over Tier 8 you can and probably should fly another signal: Zulu Hotel. It gives -10% services cost for 4 gold pieces. After T8, your services costs are higher than 60K, saving you more credits than converting the 4 pieces into credits would give.
I haven’t converted any gold to credits and not planning to do it ever. I also never played a ship that I didn’t want to play for the sole reason of “I need credits”.
Ranked is going very well (click on tiny). As much as I struggled with carriers or US DDs, the Japanese DDs come naturally: