Railfan Technology > RH77-CA Antenna

I have a RH77-CA antenna that I use on a WS-1062 (GRE PSR-500) scanner. I live on the northside of the Denver area and use the handheld to listen to the Hot Box Detector at MP 22.6 near Blue Mountain Rd on the Moffat Tunnel Sub on the UP. I seem to have better reception with the stock antenna than the touted RH77-CA. Anyone have similar or different experience with this antenna? The Hot Box Detector transmits on AAR 23, 160.455 MHz.

James Nelson
Thornton, CO
www.flickr.com/mojaveflyer

A little bit or a lot a bit? Sometimes the connector center pin gives some trouble and the antenna needs to be removed and re-attached. Or if in an active situation the antenna gets bent and there's trouble.

The more common probelms is getting intermods, but those go away too if the connector becomes oxidized or whatever.

Curious what you find.

https://www.gigaparts.com/diamond-antenna-rh77ca.html?utm_term=sku-zdm-rh77ca&gad_source=1

and many others.

https://wiki.radioreference.com/index.php/PSR-500



Edited 1 time(s). Last edit at 02/20/25 12:16 by TCnR.

The RH77-CA antenna is a decent antenna, but it is a dual-band antenna.  As such, it may give up a bit of performance on either the VHF Band or the UHF band (or both) to achieve its dual-band capability.  Also, the RH77-CA is tuned for the amateur bands--in the case of VHF, for the 144mHz-148mHz range, where the railroad frequencies are in the 160-161.6 mHz range.  So, the RH77-CA is receiving a bit out of its frequency range.  That should not be a big issue, but it could affect weak signal reception.   Now, having some familiarity from years back with the Blue Mountain repeater, you should have decent reception of that repeater in most of Denver metro with a portable radio unless there is a hill, structure, etc. blocking line-of-sight to the repeater.  If I had to guess a potential problem with your poor reception, it could be--as others have mentioned--a connector issue, or a broken element in your antenna, the latter often being hard to detect unless the rubber sheath is violated, as well.  Line-of-sight is the key for distant repeater reception.  In the Rocky Mountain region, there were numerous "mountain-top"-type repeaters where I could have good signal reception on VHF from up to 30-50 miles away with clear line-of-sight (up to 70+ miles line-of-sight with mobile radio with a permanent-mount VHF antenna).

If one is wishing to achieve the best possible portable radio reception of the VHF railroad bands, then my preferred portable radio antennas are still the Smiley 5/8 SLIM DUCK 160 MHZ, or the Laird EXH-160 series antenna.  As I've noted before, the Laird EXH-160 can be hard to find with a BNC connector, however.  Both of those antennas are about 9" long. In a shorter antenna (6"), the Laird EXB series antennas work pretty well, as do the Laird  EXS series that are about 4" long--neither has the long range of the EXH series, but aren't bad.  Laird antennas, as I noted with the EXH series, are generally getting harder and harder to find.  The Laird company, from what I've seen of late,  seems to be moving away from its long emphasis on portable radio antennas.  

It's good to have a ' spare ' antenna stashed away for comparisons, not so much a redundant, exact replacement but almost anything to work with. Those extendable metal antennas would be a good choice but are getting tough to find. Of course a second receiver would be another idea but adds to the confusion if it has broken or degraded... or has a bad antenna.

The Weather Broadcasts are a good reference, they are usually very stable and have good locations. They seem to have expanded the number of sites which could introduce some confusion. Of course checking the weather every so often is not a bad idea either.

Hope that helps.

mojaveflyer Wrote:
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> I have a RH77-CA antenna that I use on a WS-1062
> (GRE PSR-500) scanner. I live on the northside of
> the Denver area and use the handheld to listen to
> the Hot Box Detector at MP 22.6 near Blue Mountain
> Rd on the Moffat Tunnel Sub on the UP. I seem to
> have better reception with the stock antenna than
> the touted RH77-CA. Anyone have similar or
> different experience with this antenna? The Hot
> Box Detector transmits on AAR 23, 160.455 MHz.

FYI: When I bought the RH77-CA years ago I was hoping for better reception myself, but found similar results. Some regular spots were better but others not, and I just switched to the stock antenna and found its about the same overall, and easier to carry. This was in many spots in Texas and PA where I used to live, and for railfanning and photography I wasn't worred about hearing anything too far away anyways...

JG

One other note, I'm not a fan of the GRE scanners.  I have found that their weak signal sensitivity can be pretty awful.  Combine that with a potentially compromised antenna and lousy reception would be the expected result.  I would suggest trying a different radio.  My current suggestion for trial is the Qucaheng UV-K5(8) portable radio that I've posted about extensively on this forum.  A $30+/- dual-band radio that has very good weak signal senstivity and generally very good overall peformance.  It can be keypad programmed, or computer-programmed with free CHIRP software and a $15 or so BaoFeng -type Kenwood plug programming  cable.  A bonus, strangely enough, is that the "stock" dual-band antenna included with the radio is one of the best dual-band antennas that I've used on any radio.  Aftermarket free firmware improves the very good performance of this radio even more.

I had a RH77 antenna and I replaced it with the signal stick Super-Elastic Signal Stickâ„¢: BNC it is $22 + shipping if you get the black one. Other colors for more money. It outperforms the RH77 by a noticeable amount. I even gave away my RH77 along time ago.The super stick is a bit whippy and flops around a bit but it is a better antenna.  I use it on a Vertex / Yaesu VX-150 and it is a great pair for listening to railroads. I have a smiley 5/8 duck antenna and it is  also a very good antenna but the Signal Stick is just a tad better so I use that one.

Scott O'Dell



Edited 1 time(s). Last edit at 02/21/25 10:57 by seod.

seod Wrote:
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> I had a RH77 antenna and I replaced it with the
> signal stick Super-Elastic Signal Stick™:
>

Interesting. Looking at the spec sheet, is it really 19 inches or is it a wrapped up as a shorter configuration?

Receive antennas depend on exposed area for performance ( all other physics taken into account ), transmit antennas are simiar but have different issues. Having more surface area would explain quite a bit, although it looks like a simple quarter wave, following the mathmatical relationship between the two bands.Length:

• Dual band version: Approximately 19" long
• Single band 220 version: Approximately 12" long
• Single band 440 version: Approximately 6" long

I appreciate everyone's comments on my post! My primary monitoring interests are railroads and aviation. Some have expressed their like of the Chinese radios. I've played with one and wasn't impressed. I've not been impressed with Uniden radios either. I've had GRE / Whistler radios for years and find them much easier to program using the Butel software. Many of the comments echoed my observations about the RH77-CA vs the stock antenna on the GRE/Whistler radios. Thanks for your thoughts!

James Nelson
Thornton, CO
www.flickr.com/mojaveflyer

mojaveflyer Wrote:
-------------------------------------------------------
> I appreciate everyone's comments on my post! My
> primary monitoring interests are railroads and
> aviation. Some have expressed their like of the
> Chinese radios. I've played with one and wasn't
> impressed.

Please don't accept my comments as an endorsement of all Chinese radios.  A lot of them are JUNK.  I have 4 different ones that I've bought over the last couple of years that I regret purchasing, even though they were inexpensive.  I have several more that are not bad radios, but aren't up to snuff to carry regularly.  As of today, the Quansheng UV-K5(8) and its variants are the only inexpensive Chinese radios that I heartily can recommend.  In more expensive Chinese radios, I liked the very good Wouxun KG-UV6X, though it has some features that I considered "clunky."  Sadly, my UV-K6X, approaching a decade old, is having some intermittent issues with poor reception.  My suspicion is that it's having some internal circuitry failures.  There are a couple of newer model Wouxun radios that have gotten very good reviews, but they are up in the $150-$200+ price territory.  Would they perform enough better to justify their cost that is 5 to 6 times the cost for the Quansheng UV-K5(8)?  I've got my doubts.  As it is, as I write this, my Quansheng UV-k5(8) with NuNu firmware is sitting in my office right next to my excellent performing Icom IC-F3161DT and my equally excellent performing Kenwood NX-200 portable.  The Quansheng is picking up everything on VHF that the Icom and Kenwood are picking up, including very weak signals from 2 low-wattage base stations over 20 miles away.  

Yes the Signal stick is 19" long and pretty whippy the antenna can literally be tied in a knot it will even work tied in a knot. Not as well but it will work. I really like it. I have tried a few other of the 17" to 19" length range and the signal stick is the best one of them. I think the longer whip is a better recieving antenna than the smaller rubber duck's. A better antenna will make a bad radio a bit better not a great radio but better. it will make any radio a bit better actually.

I was railfanning on the Columbia river once and there was another fan there with the same Vertex VX-150 as me. I was picking up a detector  many miles away and he was not. I had a 19" whip and he had the stock antenna. It really made a difference. He very soon afterwards bought the same whip I had and he was quite happy with it.

Scott O'Dell

---

I use that antenna on my Uniden BC125AT and its a good combination, works very well!

I must second WW's opinion on the Quansheng UV-K5(8) radio.  Its is unbeleivably good for VHF rail reception (wont comment on any other).  And the included antenna si remarkably good.  At times the Quansheng, laying on the front seat of the car with the included antenna, will receive railroad converstations that neither my Kennwood D710 (admittedly a Ham receiver) or my Kenwood commercial NX-700 with external antennas receive.  Amazing radio for the price, and the price makes it almost a no risk.  The antenna alone is worth the price of the kit.

mojaveflyer Wrote:
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> Anyone have similar or different experience with this antenna?

The stock "rubber ducky" antenna that came with my cheapo Uniden BC72XLT ("NASCAR") was designed for ~460 MHz and very short distances, so using the RH77CA showed significant improvement. I tested reception of a hotbox detector 3 miles away, and the rubber ducky almost never picked it up.

I've been using the RH77CA ever since, going on ~16 years. It's been good enough for me, so the only "upgrade" I did was a magnetic mount antenna I mount on the roof, which I use a lot, on my own car, on rentals, etc. That and the RH77CA are both 1/4 wave, and I affirmed a claim in an online publication that in canyons where signals bounce around, 1/4 wave antenna is almost as good as 1/2 wave antenna. Picked up a detector almost 15 miles away inside Stevens Pass (Washington), with some static, but quite audible.

Anyway, I haven't used other antenna combinations, but some stock antennas might have loading coils ("coiled antenna") which should improve reception, which might explain your stock antenna doing better than the non-coiled RH77CA.

EOTD frequency is fairly close to 460 MHz, so BC72XLT is reliable in picking up "chirps."