RETRO RECEIVER REVIEW #11
 |
| Click on each photo for an enlarged view |
NATIONAL RF-5000
by Craig Seager VK2HBT
In today’s times, when we talk about portable receivers, images of very compact units are evoked in the mind’s eye; models from Degen, Tecsun, Sony and Grundig will often now fit into one’s hip (or even shirt) pocket. Contrast that with the products of earlier decades. For example, a few years ago I took delivery of a 1948 Mullard MBS1050 “tin” radio, complete with batteries, which by themselves weigh something like 2.8kg! Of course, that one is a tube set, but it was well into the solid-state era before anything approaching what we would now regard as “small” was produced.
In fact, there was an extended period where big was considered to be beautiful, even though it was technologically possible to produce a set that one could take to the beach without needing a trolley and hoist. This was the time of the “suitcase” radios, sold as portables but their only concession to what we now consider as epitomising the genre being a carry handle and ability to run on batteries. Manufacturers such as Sony were very active in this market segment, and models such as the CRF-160, CRF-230 and CRF-320 were substantial hunks of radio, typically darlings of the chattering classes or diplomatic corps, and indeed resembled a fully enclosed suitcase when the front covers were closed.
It is also no surprise that the rival company founded by Konosuke Matsushita in 1918, National Panasonic, also enjoyed a significant presence in this space during the 1970s and 1980s.
 |
| The earlier R-3000 receiver |
One such example is the R-3000 (pictured below), a single conversion, 6 band set from around 1965 (longwave, mediumwave, 4 x shortwave), which uniquely featured analogue level pointer displays for bass and treble, and a tuning indicator that moved between separate drum dial windows as the band was changed. A variant, the RF-3000, was more common in the U.S. market, and added FM coverage. Hard to find in good condition, and not all versions have an inbuilt rod antenna.
But it is the more upmarket RF-5000 sibling that attracts our attention this time around. This is an 11-band set, including 8 x shortwave, longwave, mediumwave and FM, originally released around 1969/1970. Lots were made! A variant, the RF-5000A, was pretty much identical, except that a multi-voltage AC adaptor was supplied as standard with the radio, rather than as an option (Part no. RD-9451).
To operate the set, each band is selectable from a row of push-button switches at the top of the radio, and there are smaller buttons for bandwidth (wide/narrow), AFC, Automatic Noise Limiter and BFO. Additionally, a thumbwheel control varies the RF gain.
The front of the radio has the main tuning control, volume, bass/treble and fine tuning, plus a battery/tuning meter – but is dominated by a large dial scale window; separate tuning indicators for FM and the rest are mechanically isolated by the band select buttons. Momentary illumination of the window is by a single small push button on the far left. Several connectors reside on the rear; FM, AM external antennas, earth, MPX out, stereo in, tape, phono, earphones/external speaker.
There are two telescopic whips, plus a loop/frame antenna that folds down at the rear. Standard ferrite rod arrangements are inside for longwave, mediumwave and SW1. The RF-5000 was promoted as having five antennae, and I guess that is technically an accurate claim.
To operate the set from batteries, one needs to invest in 6 “D” cells.
SSB reception is a little difficult by today’s standards; engage the BFO and manipulate the fine-tuning control with the dexterity of a neurosurgeon, and you’ll just about crack it. Oddly, there is a separate BFO pitch control under the battery cover at the rear.
This is quite a lively receiver when properly aligned, despite a modest specification of 10µV across the shortwave bands, and 50µV mediumwave. Selectivity does leave a little bit to be desired and front-end overloading is relatively common in high RF field strength environments, an engineering limitation of the time.
Tuning accuracy requires considerable guesswork but, hey, that is what we were used to at the time, and it was really only the professional and semi-professional sets that had any sort of bandspread calibration in 1970.
Audio is quite superb via separate 5” and 5x7” speakers, and fills the room due to the emphasis that has been placed on the output circuitry, based around a typical push-pull design. A closer look at the receive section reveals two IF stages and mechanical filtering, plus thermistors for temperature compensation. The semiconductor compliment is 19 transistors in all, mostly 2SB and 2SC series, plus 13 diodes.
Whist construction is partly modular, it has to be said that these things are a beast to service. The entire chassis has to come out in order to do anything meaningful. For this reason, unless reasonably skilled, don’t pick up a non-working example. Even simple things, like replacing one of the 13 dial light bulbs, might turn into a job best left for a rainy Saturday afternoon.
Disassembly and alignment instructions are well documented, however, if you can get a copy of the service manual (Part no. RD-410A). I found one online at http://www.kevinchant.com/uploads/7/1/0/8/7108231/rf5000_rf5000b.pdf
Otherwise, common issues include dirty contacts on the bank of band switches, scratchy volume controls, and stiff tuning mechanisms. Many examples found on popular auction sites are missing the fold-down front cover, and accordingly are worth considerably less. Best to pass, in fact. Pitting of chromed trim is also quite common, and hard to remedy.
Even more sought-after from the Panasonic stable of “giant” portables is the swanky RF-8000 (from 1976), for which some people would give up their first-born. And there is an RF-9000 (1980). Both extremely uncommon, and a mere sighting is cause for rabid salivation amongst collectors.
A sad lot, aren’t we?!
(This article first appeared in the June 2009 issue of the Australian DX News)
Once again, many thanks to Craig Seager for contributing this retro review to MEDXR, and helping to keep the memories of radio alive!
Once again, many thanks to Craig Seager for contributing this retro review to MEDXR, and helping to keep the memories of radio alive!
Missed the other Retro Reviews? Check them all out by clicking below:
Retro Receiver Review # 1 - The DANSK RX4000
Retro Receiver Review # 2 - The HITACHI KH-3800W
Retro Receiver Review # 3 - The SCHAUB LORENZ ITT TOURING T104A RECEIVER
Retro Receiver Review # 4 - The RACAL RA6790/GM
Retro Receiver Review # 5 - The REALISTIC (RADIO SHACK) DX160
Retro Receiver Review # 6 - The KENWOOD QR 666
Retro Receiver Review # 7 - The RODHE & SCHWARZ EK890
Retro Receiver Review # 8 - The YAESU FR101S
Retro Receiver Review # 9 - The SELENA VEGA B206
Retro Receiver Review # 10 - The DRAKE SPR-4
Retro Receiver Review # 11 - The NATIONAL RF-5000
Retro Receiver Review # 12 - The YAESU FRG-100
Retro Receiver Review # 13 - The MARC NR-82 F1
Retro Receiver Review # 14 - The MURPHY B40
Retro Receiver Review # 15 - The STROMBERG CARLSON AWP-8
CLICK HERE for VK3BVW Live Stream (Clublog)
| QRZ callsign lookup: |
© Rob Wagner, Mount Evelyn DX Report, and contributors 2012-2023
Great review -- on the several of these I owned, I found it to be
ReplyDeletea wonderful radio for FM, but dismal for shortwave.
this radio needs to be grounded it also works best with a outside anttn
ReplyDeletei recently acquired a rf5000 in brand new condition,,and find it to be a excellent radio with great reception on all bands....were you live could play a role..
ReplyDeleteThis is really an antique in the radio, it seems to be very familiar, because it was very popular thirty years ago.
ReplyDeleteAnyone know what an RF 5000 cost new and how to determine the date of manufacture?
ReplyDelete