N9EWO Review : Yaesu FRG-100 Receiver

The Yaesu FRG-100 HF Communications Receiver.
Was the last "HF only" communications receiver from Yaesu.
Manufactured from 1992 to 2002 ? End date is murky.
Was available for sale new for a number of years after it went out of production.
A poky seller for Yaesu over it's entire life on the market.
Please see our wide filter modifications text near the bottom of this page. (N9EWO Photo)

In late 1993 Yaesu changed the 2 wider IF filters from Murata to NTKK for tighter performance (with one filter).Great SSB audio with very low distortion, however AM mode audio only sounds average. Audio mods and our W-I-D-E filter change helps for much improved audio quality and high end, but does not totally clear up it's "woofy" sound. A small 2 way Hi-Fi external speaker helped in testing.

Country of Origin : Japan
Included (unregulated) external AC Power Supply PA-11A : Japan

Test Optional Accessories : None

Serial Number of Test Sample : 2N0302xx (manufactured in Dec 1992, number three production run)
Firmware Version on Test Sample : 1.01

Test Antenna's (outdoor) :
RF Systems MLBA-MK2 long wire (55 ft length - 24 ft height at peak)
Comet H-422 Dipole (24 ft height - Straight Configuration)

N9EWO Review : Yaesu FRG-100 HF Communications Receiver
Discontinued Receiver

PRO :
- Had a long 10 + year run on the market. (so be it was a poky seller).
- Good dynamic range.
- Excellent SSB / ECSS audio quality and performance (see con).
- Very good sensitivity.
- 2 AGC settings (see con).
- 1/2 octave front end filtering.
- Excellent image and spurious signal rejection (see con).
- 10 hz synthesizer and frequency display.
- 2 wider Murata bandwidth filters were changed in 1993 to improved NTKK ones.
- Excellent stability even without TCXO option.
- Programmable FAST tuning steps (YES 5 kHz step is available for SW AM mode tuning).
- Nice large lit (incandescent lamp) and mostly accurate S-meter.
- 52 tunable memory channels that store frequency, mode and bandwidth filter.
- All mode squelch.
- Decent LW and below performance.
- 6 and 12 db (18 db total) attenuators.
- One step dimmer (LCD backlight and S-meter).
- Continuous or on demand LCD backlight.
- Digital clock and timer that includes remote relay contacts for shoe box or other recorder / accessory.
- Main optical encoder has 2 speeds (rates).
- Band and memory channel scanning.
- Line audio output with proper buffered output (rear mounted 1/8 inch phone jack).
- Unique memory sort feature.
- Many user defined adjustments.
- Generally OK ergonomics (see con).
- No rubber track around tuning knob for better longevity.
- Hard plastic buttons with Tac switches for excellent tactile response.
- Solid tilt bail that includes desktop protection.
- Included carrying handle included as stock (see con).
- Solid vinyl-clad steel outer case that uses machined screws (no self tapping ones here).

CON :
- Extremely poor internal speaker.
- A fairly noisy synthesizer (but as expected in this price point).
- Test sample suffered from digital buzzy sounds in sub audio (this appears to be a common trait, easy fix see text).
- Muddy AM mode audio quality (a super wide IF filter and other mods help, see my test below).
- Reports that certain VCO ranges can fail (band dropouts).
- Non-selectable 10 db MW band attenuation.
- AGC has a tad slow decay rates (in both fast and slow settings).
- Only ONE VFO.
- No direct keyboard entry.
- No Notch or Passband tuning.
- Nonstandard DC input jack.
- No tone control.
- No Rf gain control.
- Poor noise blanker.
- It's optical tuning encoder and spring tension assembly can get tight to extremely tight due to aging grease.
- Clock shares with the frequency display (not so handy).
- LED backlight can fail due to a power resistors that looses connection on PC board due to heat stress (from reports, see text).
- Rear antenna switch can become dirty (bad connections) in it's old age (easy fix).
- Tac switches are known to become intermittent with some samples.
- Sticky S-meters but is not a common failure (just like the Sony CRF-320 / 330 and CRF-1).
- FM broadcast breakthrough is a common bug for users that are near VERY STRONG FM broadcast transmitters (as experienced with the test sample).
- Flimsy carrying handle (DON'T USE IT).

Size - Weight / Vinyl Covered Steel Cabinet / 10 hz Tuning / DDS / Carrying Handle

The Yaesu FRG-100 is a standalone table top communications type radio receiver with Long Wave , Medium Wave and Short Wave with full coverage from 50 kHz up to 30 MHz continuous (USA version). Dual UP conversion design with 47.210 MHz first IF (intermediate frequency) and 455 kHz as the second. Size is a compact 9.0 W x 3.6 H x 9.3 D inches (238 W x 93 H x 243 D mm). A fairly lightweight cabinet at only 6.6 pounds (3.0 kg), not including the included 12 volt DC 1.5 amp PA-11 unregulated power supply (which is near half the weight of the receiver).

Cabinet is made out of heavy steel that is not painted. Has a black vinyl coating and the test sample has held up well here. There is a plastic carrying handle on its right side, but here it is quite flimsy and we don't recommend using it ! All cabinet screws are of a machined JIS type (no self tapping screws used with the outer cabinet). Has a excellent tilt stand that includes rubber protection for the tabletop.

Top RF PC board and the bottom synthesizer / VCO board are made out of good old brown phenolic material. While the from panel boards are of a higher standing fiberglass epoxy type. Hybrid construction using standard leaded parts on the top and with just about all transistors (but also resistors and capacitors) are tiny surface mounted types underside.

High tech DDS (synthesizer) is used in the receiver. As is the case with many communications receivers of this era and price point, the synthesizer is rather noisy. Frequency resolution / tuning rate steps is minimum 10 hz and is displayed on the LCD. The10 hz digit can be turned off if desired.

Ergonomics / No Direct Keyboard Entry / Aftermarket Devices

Ergonomics are decent and logical. All buttons use very easy to press hard plastic that use separate tac switches (no PC board membrane type buttons or carbon backed buttons used here).

One major drawback is the lack of direct keyboard frequency entry. One can offset this by using the memory channels to give "presets" near the frequencies of interest as all memory channels are all tunable. Over the years there were a number of after market products that gave direct frequency entry. But reports indicated that in some cases these devices (plugged into it's rear panel CAT port) created digital noises on received signals (not tested).

Optical Main Tuning Encoder / Weighted Tuning Knob with Set Screw / Aging Grease Makes Rotation Stiffer Than it Should Be

It's main tuning encoder is of the optical type. Knob is weighted and uses a single set screw for attachment. Spinner hole is fixed (that is has not moving piece). If one removes the main tuning knob you will see a plastic insert over the encoders bearing / mounting nut.

OBSERVATION : We found in testing that if one tightens or loosens up the spring (by moving the little end piece as marked in the photo below clockwise or counter clockwise around the white plastic shaft) the knob tension is adjusted. This is not official information and is not covered in the manual. WARNING : If you attempt this are totally on your own and at your own risk !

Encoder has a good solid feel but it's internal grease tends to get gooey / tight with age, so perhaps even if you adjust the spring, you could still experience a tight encoder. This usually requires that the encoder be totally taken apart and the old grease be removed and replaced. Some have reported to just let a small amount of Deoxit D5 dribbled down the shaft (with the receivers rear panel placed on table top for awhile, so with the front panel upright, not tested).

The "Memory Channel" encoder is most welcomed feature (and not being accessed by UP DOWN buttons). However uses a lower cost mechanical type. Anyway it has a excellent feel (not a clacky type and has zero play). With the test sample it rotated a bit on the stiff side, not sure if this was due to old age / grease ?

The FRG-100's Tuning Knob Tension Adjustment (spring) ?
Turning the arrow marked spring (totally around it's white plastic shaft)
end loosens or tightens its knob tension (see text) ? (N9EWO Photo)

I will NOT be held responsible for any info that is listed here
ALL DONE AT YOUR OWN RISK !

Nice High Contrast Easy To See LCD / Dimmer / All Mode Squelch

LCD has a excellent DARK contrast. Has no way to adjust it and does not need it (it's perfect). Display backlight uses LED's and the S-Meter a single 8 volt wired incandescent bulb. There is a dimmer button (LCD and S-meter) and is most needed as bright was not useful to our eyes and with indoor conditions (most will keep it in Dim position).

TIP : If your LED backlight fails, check the 2 resistors in the left FRONT corner of the top MAIN RF / AF board for cold solder joints. These resistors all run on the toasty side. This will require you to remove this PC board to check and re-solder these connections.

R1169 33 ohms 1 watt
R1174 10 ohms 1/2 watt
R1177 22 ohms 2 watt

Excellent all mode squelch and is tied into the record relay (rear jack). Only caveat here is every time the squelch opens up you hear the relay activate (a click).

Highly Programmable User Defined Settings / 2 AGC Settings

There are 25 user programmable toggles / adjustments with the FRG-100 (see chart below). One can even reduce the encoder speed in half (and is highly recommended as it's not set aa default).

AGC decay rate has 2 settings (Fast and Slow). Even in the fast setting it still seems to be a tad too slow for some.There is no AGC off and being the receiver lacks a RF gain control makes sense. In any event the AGC performs well indeed.

YAESU FRG-100 Options Setup		via Keith Browning - "groups.io" FRG-100 forum

Power-up Functions	Hold and turn on	Comments

Default display	VFO/MEM	Toggles display between frequency and time.
Erase ALL Memeory info.	MEM CLEAR	Clears all memory channels, returns radio to default settings
FAST tuning rate	VFO>MEM	Halves the default tuning rate
Memory Frequency Sort	MEM>VFO	Arranges memory frequencies. Low to high.
Front panel lock	LOCK	Locks all front panel keys
12 / 24 Hour display	CLOCK	Toggles 24 and 12 hour format.
Hourly beep	TIMER	Emits 3 beeps every hour.
Scan stop	SCAN	Scan resume must be manually initiated.
Selects scan mode.	SCAN SEL	Toggles between group channel and group letter scan.
10Hz Digital scan	DOWN V	Turns off the 10Hz digit.
FAST key function	FAST	Selects continuous or momentary type.
Scan resume operation	SEL	Toggles Carrier and Time delay scan resume operation.
Select CW Sideband	CW/N	Permits matching CW carrier offset to LSB or USB.
LCD Backlight	DIM	Selects continuous or momentary LCD backlight.
Receiver Diagnostic Test.	SET	Performs self test and displays CPU version number.

SET Functions	Hold SET and press:	Comments

Beep tone	VFO/MEM	Adj. Beep tone from 270-3520Kz (880Hz default)
Enable / disable beep	VFO/MEM then SEL	Enable / disable beep.
SSB carrier offset	MEM CLEAR	Adj. SSB carrier 452-458kHz to tailor freq response. (453.5kHz)
CW Note	VFO>MEM	Selectable 400, 500, 600, or 700Hz beat note.
Custom Tuning Steps	FAST	Selectable tuning increments from 100Hz to 100kHz
Broadcast Band selection	UP^	Selection of 16 international broadcast bands.
IF Bandwidth selection	SEL	Selectable default IF selectivity for each mode.
Reverse BFO offset	CW/N	Places BFO offset below or above (default) IF center frequency.
PLL Offset	MEM>VFO	Permits fine tuning +/- 3kHz of local oscillator
Memory scan skip	SCAN	"Locks out" a memory channel from scanning.

Programmable Tuning Steps for Tuning Knob / 52 Memory Channels With Sort Feature / Battery Backed Memory Channels / Clock -Timer - Sleep Functions

With it's programmable step feature, one can adjust the tuning step from 10 hz up to 100 kHz. So yes it is possible to have 5 kHz step in the SW broadcasting bands (as is 9 or 10 kHz steps in the MW band, however it does not have separate settings for just MW, so keeping it in 5 KHz steps makes more sense). However this is a bit touchy even with the encoder speed turned down to half (but we adjusted to it).

52 memories are available (50 regular with 2 scan Hi and Lo that can double for 2 extra ones if scanning is not desired). Memories store frequency, mode and bandwidth. These are battery backed using a REPLACEABLE and common CR2032 coin lithium battery so is very easily dealt with. Yes the battery is mounted in a socket, unlike with the JRC NRD-525 and NRD-535 models that are soldered into place. This battery also backs up the user defined function as shown in the chart above. Manual indicates it has around a 5 year life span. There is also a tiny switch to turn off the back up battery if desired.

2 clocks (12 or 24 hour format), a timer and sleep function are all featured. However the clock shares with the frequency display (so you cannot have both at the same time). Also you cannot have one clock in 24 hour mode and the other in 12 hour which is pity (even if the manual says you can...it's WRONG). Sadly the clock was not as useful as it could have been as the test sample kept awful time. Gaining a good minute in just a week or so (another old age issue ?).

Scanning can be done between 2 frequencies OR you may also scan the memory channels. Certain memory channels can also be locked out. Default is a excellent timed scan resume (that is once it finds something it will continue in 5 seconds just like car radio). This can be changed in the user defined menus (see chart) where you need to press a buton to continue..

Sleep feature allows you to set the off time for up to 2 hours.

Very Good Sensitivity / Antenna Connections / IF Filters Changed in 1993

Sensitivity is very good if not excellent. Full level and without the use of preamps and other switches. Clean hiss free operation too.

SO239 antenna connection as well as a balanced clips (speaker terminal type connections). A very tiny recessed switch selects between these which makes for a bit difficult use (have a toothpick handy).

FRG-100's IF Filters were changed in late 1993. When released in 1992 the 2 wider filters were the plastic case 6 element Murata CFW455H and CFU455I (Note : Are NOT the T versions of these filters) and for the narrowest (normally used on SSB) filter is a 11 element metal cased murata CFJ455K15 (about 2.7 kHz). In late 1993 they switched the 2 wider ones to NTKK LF-H2S and LF-H6S. One being a bit wider than and one narrower vs. the murata's. The excellent CFJ455K15 exists in either version.

Neat part is the user can place any filter on any mode (see chart above). So one can use the CFJ455K15 in the AM mode if desired. We tested a wide filter modification to help improve the FROG's difficult AM audio quality. Please see that information near the bottom of this page.

FRG-100 IF Filters came in two versions.
Starting in 1992 the plastic 2 wider filters were Murata CFW455H and CFU455I.
In late 1993 they were switched to NTKK LF-H2S and LF-H6S.

NO RF Gain or Pass Band Tuning / Dynamic Range Decent / 2 Attenuators

Missing on the FRG-100 is a "RF Gain" or "Passband Tuning" controls / features. Being the AGC adjustments do not offer a OFF setting, this is adequate with it's price point.

2 antenna attenuators are selectable via the front panel (no reaching to the real panel). One being 6 db and 12 db (so you can have a total of 18 db of attenuation). They use 2 relays, so a click is heard when activated..

Good news is we never had to make use of the attenuators in the testing period as it's dynamic range behaved itself very nicely. Not once did it overload with our test antennas and Midwest USA location.

Decent Front End Filtering / MW Broadcast Attenuator / Image Rejection - Spurious Rejection Excellent Except for FM Broadcast Breakthrough

Above average front end filtering with the FRG-100. 8 filters are used (1/2 octave). Unlike many other table top receivers, the long wave band is free from ANY medium wave intrusion (zippo). WWVH on 60 kHz was clearly received with no spurious junk mixed in.

FRG-100 Front End Filters
0 to 0.5 MHz
0.5 to 1.8 Mhz *
1.8 to 3.0 MHz
3.0 to 4.0 MHz
4.0 to 6.5 MHz
6.5 to 10.0 MHz
10.0 to 17.0 MHz
17.0 to 30.0 MHz
* - 10 db always engaged attenuation in the MW band

In general spurious signals were not excessive (only found 6 and and these were synthesizer birdies)...but not so fast ! Downside is if you live near any FM broadcast stations you can expect some signal intrusion. At the test location a 200 watt FMBC station on 100.3 MHz was clearly received around 1960 and 5880 kHz without ANY antenna connected at all (at 1.5 miles [2.4 km] away). However as bad as this sound it was never a nagging issue in use, but could be if near a stronger transmitter (not tested).

Mediocre AM Audio Quality / Proper Line Output Jack / "Beep" Audio Line Produces Microprocessor Noises / Dreadful Internal Speaker

A already well known trait is that the FRG-100's AM mode audio quality is what we and others call "woofy". That is it contains a bassy and somewhat distorted sound. Mind you it's not as bad as say a Icom IC-R71A or RadioShack DX-394 (ARF !), but not going to sound like a Lowe table top set either. SSB modes are a aural treat and a totally different story. Here it's is very pleasant sounding and way above average.

ECSS is more than possible and easily tuned. If you only use the 2.7 kHz filter, then ECSS will be no problem and excellent. However if you try and use wider IF filters, then it's not so great with the 10 hz tuning minimum tuning step. So a 1 in 10 chance to sound right, but if you get lucky with any given signal, ECSS sounds and works great as well.

General audio quality has not one hint of sub audio amplifier "hissy-ness" or power supply hum with the included PA-11 power supply. That is excellent indeed ! Speaking of the included UNREGULATED PA-11 power supply, it operates the receiver just fine with only moderate heat. It can be taken apart (it's not welded or glued together), however it uses some strange security screws. UPDATE : Appears that later manufacture of the PA-11 power supplies are sealed (are not easily taken apart).

There is one little bug-a-boo that involves the keys "Beep" feedback sound. This appears in the receivers sub audio as intermittent groans and clicks.

Listen to our MP3 audio file as recorded from the test sample here (NOTE : I has been slightly edited with increased volume, it's not quite this loud).

Turns out this is caused by gremlins being emitted out of the microprocessor and irks into the audio chain via it's beep line. One can just turn off the BEEP and it's gone (see above chart). But we desire to have some BEEP feedback when pressing buttons (and for the neat top of the hour "3 beeps"). So the cure is to just FULLY adjust the "Beep" level control on the MAIN RF / AF board VR1005 to minimum (fully counterclockwise), and this issue is fully cured too. Even with the control fully turn down there was still enough Beep left to satisfy. Please see page 31 in the owners for more details on how to do this. UPDATE NOTE : A reader has indicated to me that this bug varies from sample to sample.

Rear mounted "audio line" output jack has the perfect and CLEAN output level (a 1/8 inch MONO jack). It has a transistor buffer amplifier stage too. Yaesu did this right !

As it goes on most tabletop receivers, the internal speaker is simply dreadful. Actually it has to be one of the worst we have ever tested. A external speaker is a REQUIREMENT with the FRG-100. Using a small and efficient 2 way hi-fi speaker type is most recommended.

EIAJ DC Power Input Makes for Difficult Power Options

Yaesu decided to make use of a dreaded EIAJ power input connector. These are very strange power plugs / sockets. They use a MALE pin inside the plug end. Yes you guessed it , Icom also uses a similar type plug with the more current IC-R8600 receiver (that is if you use that power input).

Has been reported that the Philmore # 255 plug will work but the plastic tip MAY need to be filed down so the center tip makes contact. We have not verified this information. Would the Philmore # 265 work better (not tested) ?

Nice and Stable Even Without TCXO-4 Option

We found the FRG-100 to be extremely stable even without the TCXO-4 option (which was not installed in our test sample).

As can be figured with this last FROG being discontinued now for many years the TCXO-4 high stability crystal option is no longer available from Yaesu. If one hunts around on ebay, a number of after market ones are for sale. WARNING : We have not tested nor can we recommended any of these.

Yaesu's FRG-100 rear panel. Has all of the right input and output connections. (N9EWO Photo)
Only bug-a-boo is the use of the dreaded EIAJ power input connector.
Philmore # 255 plug wili work but the plastic tip MAY need to be filed down so the center tip makes contact.

Sticky S-Meter Syndrome Has Been Reported

Just as with the Sony CRF-320, CRF-330, ICF-6800W and CRF-1, reports have indicated that some FRG-100's S-Meters can get "sticky". Well it's not really sticking (needle stays locked in one spot even when off). It's caused by the spring action in the meter that becomes loose from age. In the case of Sony meters, one can fix these by just adjusting the zero setting screw on the front of the meter below zero. Uncertain if this method would work with the FRG-100 ?

I will NOT be held responsible for any info that is listed here
ALL DONE AT YOUR OWN RISK !

Overall a Nice Desktop Receiver But Make Note of it's Audio Distortion in AM Mode

The FRG-100 is a respectable set. Fun to use and MANY user defined settings that makes it highly adjustable to ones desires. Nice high contrast sharp LCD with a excellent backlight.

However make no mistake, it's AM mode audio quality while not as bad a Icom IC-R71 or Radio Shack DX-390 (again ARF !), is still only mediocre. On SSB / ECSS modes this is not an issue (sounds beautiful). Please see the WIDE filter change modification below for improved AM mode audio quality.

Yaesu made quite a number of the FRG-100 over it's 10 year (plus) run on the market, so used samples can be found fairly easy on the used market. As usual the condition and proper operation varies greatly (so buyer beware, the usual Caveat Emptor).

Yaesu FRG-100 Serial Number Labels

Here are the serial number labels used with the FRG-100.
Including when Yaesu became "Vertex Standard" for awhile.
First number and letter indicate the year and month of manufacturing (C being January).
The next 2 numbers are the lot (production run number).
Incorrect information has been floating around the internet on this and to set the record straight !