Tag Archives: Harris RF 505A

Nick acquires a Harris RF 505A receiver

Many thanks to SWLing Post contributor, Nick Booras, who writes:

I just picked up a Harris 505A and I made a couple videos your viewers might like.

This radio is extremely sensitive as you can see in the comparison videos. I am very lucky to have picked it up. I will add that in the comparison to the Kenwood TS890 I didn’t try the 15 kHz filter on video. I did try it afterwards and I was surprised to receive the weak 6.085 signal with similar results to the 505. I thought for sure that that huge width would only let in more noise but I was wrong. I learned something new! But the 505A is still a super sweet machine.

Thank you for sharing this, Nick! What a wonderful addition to your radio collection. I’ve always loved the incredibly simple design of the 505A and have assumed it would have a very low noise floor.

Thanks again!

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Seyfi is seeking Harris RF 505A documentation

Many thanks to SWLing Post reader, Seyfi Genç, who writes:

I’m a strict follower of your blog and of course a SW listener and HAM (TA2MOK) from Istanbul Turkey.

I bought a Harris RF 505A last week for just $30 US!

I need to datasheet to repair it.  I didn’t find it on internet.

Thank you.

Wow! You bought an RF 505A for $30? Amazing!

Post readers: If you can help direct Seyfi to RF 505A schematics or a repair manual, please comment with links!

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Bob recalls working at Harris and putting the RF-505A on the air

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In response to our post mentioning the Harris RF-505ASWLing Post contributor, Bob LaRose (W6ACU), writes:

I know the RF-505A very well. It was introduced in about 1969 while I worked at Harris in Rochester. I started working there as a Co-Op student while at RIT and then after I got my BSEE I joined them full time, initially as a Field Engineer but quickly found my way into Marketing and eventually Sales.

Right after the first version came out, the RF-505, I took one home to my parent’s house for a weekend and did some SWLing with it. It was very neat in one respect – it tuned ISB (Independent Side Band) and in those days there were a number of utility stations using ISB (separate traffic on each sideband). To an SWL some of the most interesting of these were the VOA point-to-point links from the East and West Coast, each carrying two simultaneous program feeds for the overseas relay stations!


While overall a good receiver my personal results on the sensitivity of the original RF-505 were not very positive. On the bench with exactly a 50 ohm source it looked good but on a real world antenna it was pretty numb. Eventually, after a lot of internal arguments, they came out with the RF-505A that included a tunable active preselector as shown in the photos. Problem solved.

For a ham or SWL the RF-505 was a real pain in the butt to tune. You could dial in any exact frequency but the decade switches didn’t roll over (either mechanically or electrically) so you had to do a lot of knob twiddling to do any kind of band scanning. The detents on the switches connected to the knobs were pretty stiff so you could easily take some finger skin off tuning around!

If I remember correctly Harris built them for about a five year period and then replaced them with the RF-550, which was a monster of a receiver with all kinds of advanced features. It included a keyboard with electronic display.

Great memories!

Thanks so much for this RF-505A insight, Bob! I had a hunch that band-scanning wasn’t the RF-505A’s strong suit–it would be incredibly cumbersome to scan with so much “knob twiddling.”

It must have been pretty amazing to work for the legendary Harris corporation. Thanks for sharing!

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Dan notes some rare Harris, Microtel and Drake receivers on eBay


Harris RF 505A

Many thanks to SWLing Post contributor, Dan Robinson, who writes:

These days as shortwave continues on the decline, we’re seeing some great rarities, receivers that have never been seen before on the used market. One of  these is [top of page], a Harris RF-505A.

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Click here to view the RF 505-A on eBay.

Another rarity, is a Microtel PR-700B receiver, information about which
can be found on Page 355 of the Osterman master guide to receivers.

Model PR-700B

Microtel Model PR 700B

Click here to view the Microtel PR-700B on eBay.

Last but not least, and this has never been seen before — a Drake DSR-2, apparently unused in its original packaging, which sold in flash for about $1300:

The Drake DSR-2

The Drake DSR-2

Click here to view the Drake DSR-2 on eBay.

Thanks, Dan! I’m a little surprised you haven’t at least jumped on that Harris receiver! I would be very tempted if I had the shelf depth for a rack-mounted commercial receiver.

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