Based on the Ilford MSDS information, it appears that Ilford HYPAM and Ilford Universal Rapid Fixer are the same fixer.
Ilford Universal Rapid Fixer contains Ammonium Thiosulfate, Sodium Sulfite, Sodium Acetate, Boric Acid and Acetic Acid. The pH of the Ilford Rapid Fixer concentrate is listed as 5.1 (thus acidic)
Recall: Acid pH is less than 6.5
Neutral pH is 6.5 to 7.5
Basic pH is greater than 7.5
If you wish to increase the pH (i.e. make the fixer alkaline), just mix in Borax or Sodium Metaborate until the pH reaches the desired level (i.e. approx. neutral pH when the fixer stops fizzing - then add a few more grams of alkali). Otherwise, you would need a pH meter or pH indicator paper to accomplish this.
I have great success developing with Wd2d pyro developer and fixing in Kodak Rapid Fix, just omitting the hardener (which comes in a separate bottle) from the fix mix.
Both Kodak Rapid Fix and Ilford Rapid Fix are acid. Consider adjusting the pH of the working fixer bath to alkaline by adding Borax (Sodium Tetraborate) or Sodium Metaborate. Try 10 to 15 grams of Borax per liter of working fixer.
Sodium Metaborate is a good option - but may be hard to find outside the USA.
The rest of world does actually have access to things like um, you know, chemicals and stuff... Sodium Metaborate is the stock soln. B and I still have some unmixed - off to get me some litmus thingies
Cleared the bowel problem, working on the consonants...