There has been much to-do about the Sony SRF-39 "Ultralight" over the years.
The latest was a newspaper article on the clear case FP jail version...
the article inferred that maybe this version was more durable,i.e. the variable cap
was not subject to the dreaded "Rice Krispie" snap crackle and pop defect on AM
due to use of poor (cheap) paper dielectric material.
Unfortunately that has not been seen here...brand new FP versions have it,as well
as new vintage Malaysia-built SRF-39's which are supposed to be good.
It appears the defect is found in all these caps,whether they're in a 39,49,59,SW-10,11 etc.
Just comes with the territory.
One result of the article was to run the ebay price of the FP version
up from the usual $20 or so to well over $100...they are back to normal now.
But now for a just-discovered secret:it's possible to -maybe- get around the variable
defect by use of a pre-ultralight Sony:
Back around 1987 Sony came out with the SRF 19w and then 21w.
If they look similar,they are.Who knows what Sony was
thinking (they did the same thing with the first-generation
SRF-33w and 22w BTW).
But both have performance that is very very close to
the 39 family Ultralights.The variable however appears to be a
different type since these were made in Taiwan.
No snap,crackle or pop was heard on these.
What was heard was excellent sensitivity/selectivity.
Use of a 3 volt supply gives the audio real punch,too.
On FM they do very well,especially on low power
The 39 family has afc problems with adjacent
Not these,they slice and dice quite nicely.
Typically they go for $15-30 on ebay.
What to look for:
The top dial cover was hot glued on;if the
pointer sticks check for this.
The off-on switch is a real pain to remove and
put back on...it's like they wanted to make
it as hard as possible!
Tuning is a little "firm" due to use of dial cord...
these may have been the last to use dial cord
since the follow-on SRF-29 had the current
plastic pointer setup.
All things considered they are worth a go.