fisher stereo

It’s possible, but the easy solution is an adapter. There’s one on Amazon- search on “CESS-104 RCA Plug to Female Banana Jack Adapter Cable, 2 Pack”.

Bingo.
https://www.amazon.com/dp/B08FG4NW4F/ref=cm_sw_r_apan_glt_fabc_JG7VVTD3P3GTF5X2XEZC
They look good to me.
I doubt there is room on the back of the receiver to do any better. And you shouldn’t alter vintage stuff anyway.

Keep in mind that the older stereo compacts with RCA jacks for the speakers were rarely that powerful.  Not sure what speakers you were planning to use, but they would need to be fairly efficient.  

Good luck.  I had a SONY HP161 compact in HS & college that I just loved.  

Rich 

Thank you for all your help. I will take a look at the amazon speaker cables. That would seem like a much easier solution. The sound on the Fisher was good for a while but the original speakers gave out too quickly.My dad never bothered to replace them at the time so we had just bought another stereo later on. I didnt know that  he kept the Fisher and he  just unboxed it recently. It would be nice to use it again as a secondary stereo and one that he is familiar with.

Hate to be a downer but…as rar1 suggested, I’d be shocked if that item has as much as 5W @ 10% THD. Those ‘70s compact systems were not all that good. Don’t expect too much. KLH made pretty good ones, but Fisher, not so much. 

https://www.analogalley.com/osccart/product_info.php?products_id=1368

...spend another 14$ for the pdf of the original owners' manual, and it might give a hint as to what its' specs really were (maybe)....*S*

Sometimes things are worth more than their specs or the relative worth to others....;)

Enjoy, even if only for memories and for Dad.

Even crustycoot should give that a nod.....

I don't expect the stereo to sound anything  like modern systems, so there wont be any disappointments. Initially, its'  sound was decent before the speakers gave out. If it works out well with the new speakers, that would be great. If not, no big deal.  I was surprised my dad still had it. We'll see how successful it will be once I get the speaker cables. 

Do you know it works? If it hasn’t been used in a long time, be prepared for the worst, especially if you power it straight on to 120vac.

The speakers that came with these systems were extremely efficient full range types.  I'd suggest actually looking for another pair in thrift stores.  Something from the same era by Emerson, Soundesign, Lloyd's, and similar.  They will also have RCA plug type connecter.  The other folks here are right, in that it would be very disappointing with modern speakers.  

And if you want to get real fancy you could also get something like the Audio Engine B1 Bluetooth that will connect to your Aux RCA and stream music via Wi Fi for low cost

Thank you for the info. I dont want to complicate the stereo for my father's use,  so streaming anything would be out of the question for practical purposes. I appreciate all your suggestions.