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Reviews For: International Radio (Inrad) IF Filters

Category: Filters, RF: bandpass, duplexer, lowpass, highpass, RFI/EMI

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Review Summary For : International Radio (Inrad) IF Filters
Reviews: 73MSRP: 115-155
Description:
Filters
Product is in production
More Info: http://www.inrad.net/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00734.8
VK3ZGP Rating: 2021-12-10
SSB Filters For Yaesu FT-897 Time Owned: more than 12 months.
QRM is a significant problem at my QTH due to electric fences used in the vicinity for livestock, plus four High Voltage transmission lines that cross the property, plus limited options for antennas. The house is adjacent to a 128KV, a 220KV plus two 500KV transmission lines.

INRAD offered a wide range of Collins mechanical filters from 300Hz to 5kHz for the FT-897. Unfortunately the FT-897 can only accommodate two optional filters. The filters are on carrier boards that simply plug in. To change filters is a simple procedure of removing the top cover and carefully disconnecting the speaker wire.

As expected (with default DSP settings) the narrow filter digs weak signals out of the noise with the loss of fidelity, while the wide filter improves fidelity of some signals at a cost from the rise in noise.

The FT-897 allows you to rapidly swap receive fiters using the front panel keys (menu MFn) and uses links hardwired on the optional filter boards to display the bandwidth on the FT-897 front panel. Yaesu appears to have limited the display programming to suit their 300Hz, 500Hz and 2.3kHz Yaesu filter boards therefore the INRAD SSB filters equal or greater than 2.3kHz all appear on the FT-897 display as 2.3kHz filters. As they are selected using different front panel keys and you can hear significant audible differences between the INRAD filters I don't confuse selection.

In Menu Mode No 86 [TX IF Filter] there is the choice of Yaesu's inbuilt ceramic filter or either optional filter. This is independent from the receive filter selection. Again Yaesu displays the programmed 2.3kHz labels for INRAD filters, and not the actual bandwidth, nor the filter slot number. In this menu option the front panel keys are not used and Yaesu uses a small rotation of the main Dial to select different filters. This is not an issue when there are distinct labels (eg, a CW with a SSB filter). But with a pair of INRAD SSB filters there is the real possibility of confusion. As it can be difficult to determine which INRAD filter is being selected I place the 2.6kHz filter in slot 2, spin the main dial to skip slot 1 and select the 2.6kHz filter for transmit. It should be possible to select the narrow slot 1 filter if you stop main dial movement at the instant the display changes fron CFIL to the 2.3kHz label. At this stage I have not experimented with this option on-air.

The FT-897 TX metering displays the modulation percentage before the TX filter so changing filter selection does not change modulation meter reading but filter changes may be reflected in the TX power metering (worst case is SSB TX through a 300Hz CW filter, modulation meter reading still peaks to 100% and nobody hears you).

I'm satisfied with the performance of the filters while the display limitations are not significant to me, outside the control of INRAD, and inherent in the FT-897 design.

Collins have stopped manufacture of mechanical filters. As INRADD sells out their current stock there are no substitutes available and products are being deleted.
N2JTX Rating: 2020-07-10
Noticeable Improvement Time Owned: more than 12 months.
I picked up an INRAD #720 filter on New Years Day in order to get their one day $20.13 off discount. The filter installed easily in my FT-897D and activating it through multi-function row "MFn" is easy. With the filter engaged, there is a noticeable drop in background noise and a slight reduction in fidelity which is to be expected going from the stock 2.7kHz filter to 2.0kHz. I have noticed that tuning is a bit tighter due to the narrower passband. As of this time, I have not had a chance to test the filter on a crowded band to see how adjacent signal rejection is working. That will probably have to wait until either the ARRL DX SSB or CQ WPX contests in March. I also need to test menu option 086 to see what difference the filter makes on my transmit signal. So far, I have not had a chance to setup a QSO with someone to do a comparison.

UPDATE: I noticed I posted this almost 7 years ago. I wound up making a slight change to the #720 board by grounding PIN 6 of the board (there is an open jumper position on the board to do this). Once this is done, it is possible to set a custom filter name on the FT-857/FT-897 using Menu Option 64. Without this modification, the radio assumes the filter is a 2.3kHz Yaesu YF-122S filter and will display information for that filter on the menu. Using Menu Option 64 and the PIN 6 jumper, it is possible to set a custom name which I set to "2.1K" for this filter.
N2SCL Rating: 2014-05-18
Probably the Best bang for the buck ! Time Owned: 3 to 6 months.
These filters were the least expensive (new) and had the greatest ratings. I purchased (direct from InRad) the 2.0 kHz (#720) and 2.9 kHz (#726) filters for Yaesu radio, and a 250 Hz CW filter (#122) for Icom radio, and all were excellent performers. Highly recommended ! GC
F6DEX Rating: 2014-03-06
Mediocre substitution Time Owned: 0 to 3 months.
I bought a 400 Hz 8830.7 kHz CW 8-pole crystal filter for a TS-120V. The specifications do not indicate clearly that this filter does not fit the IF board and has to be wired with a - long - coax (no place available immediatly near the location). The filter itself may be good but such installation is not optimal and degrades isolation of the filter which increases the "blow-by" effect (depending on how you arrange the coax). Insertion losses are + 8 db( vs stock filter). Disapointed.
NT9M Rating: 2014-01-31
Inrad 92 + TS-2000 Time Owned: 6 to 12 months.
Just worked my second 160 meter contest with the 92 in my TS-2000. I didn't write this review after the first contest because I thought it was the propagation conditions that made the contest such a pleasure. But for the second straight time my receiver was so much better than before that I have to admit that the Inrad 92 has tamed this radio. It was an abomination under crowded contest conditions before. Thanks to Inrad for working with Cliff at AVVID when a problem arose. Great service and a worthwhile add to the TS-2000.
W6LBV Rating: 2014-01-12
"IN RAD WE TRUST" Time Owned: 0 to 3 months.
I had long wanted to upgrade my revered Kenwood TS-850 transceiver with an additional IF filter, but the task never quite rose high enough on the revolving priority list. Last December I glanced at the Inrad Web page and noticed a special “New Year’s Day” discount offer on any filter purchase. Then I jumped for it and ordered via their Web page the #95 filter, a 1.8 kHz passband SSB filter for the high IF. It was my first purchase from Inrad.

What a quality company! Every step in the ordering, delivery, and installation process occurred exactly as described. There were no surprises, no disappointments. The promised discount automatically appeared on the order form . The two-day ground delivery service was exact. The product was well packed and arrived in factory-new condition.

Inrad even discovered that they had overcharged me on the sales tax, and on their own initiative
corrected the order and refunded the difference into my credit card account. Only then did I discover their error.

For anyone who is yet to install a filter into a TS-850, here are some notes and corrections. Both the original Kenwood manual and the instructions packed with the filter are vague in a few details, and the two sources occasionally conflict with each other. This is what I found.

1. To reach the bottom PC board where the filters will be installed, it is necessary only to remove the inner portion of the bottom cover, the little “hatch” secured with two bolts and two hinges. It is not necessary to remove the entire bottom cover or to go farther into the radio.

2. The filters fit precisely into the indicated areas of the board and two slots for two filters are available. You can use either of the two filter slots, and it makes no difference which one you use. Likewise, the filter input/output is electrically symmetrical, so end-for-end orientation of the filter on the board is not a consideration.

3. To mechanically mount the new filter, as indicated on the Inrad instructions, you will need to cut off two metal pins sticking up from the board on just one of the two symmetrical “five pin electrical connectors,” These pins provide signal connection into and out of the filter. The equivalent Kenwood OEM filters do not require pin cutting. Do not fear cutting the pins; they have no electrical function in the radio.

4. One position on a little four pole wafer switch located under a hatch in the top cover needs to be flipped “on” in order to activate the installed filter in the IF circuit. For the high IF filters, switch positions 3 and 4 activate the two filter slots. Try both positions, sequentially. One of the two positions will work, and it’s hard to predict which one that is.

5. The Inrad instructions call for a full reset of the 850's on-board microprocessor after the new filter is installed. The Kenwood manual does not call for it. I did the full reset.

The filter has worked exactly as expected. I measured the effective filter passband using a synthesized, calibrated signal generator and the transceiver as a null detector, and found it to be 1.7 kHz at the 6 dB points. That’s within measurement error. I did not measure the installed filter for its specified insertion loss. Operationally, the filter makes a large improvement in SSB reception when the bands are crowded.

It isn’t often when the acquisition of a new piece of hardware goes perfectly from end to end. Inrad is indeed a quality company!
W8AAZ Rating: 2013-12-16
Help for old rigs Time Owned: more than 12 months.
I remember many many years ago plopping a 2.1 KHz SSB filter into an FT-101 I had, and getting much better selectivity. Was something like a Fox Tango or such? I got another FT a few years ago and popped a 2.1 INRAD in it. So much tighter on receive but not too narrow sounding like maybe a 1.8 would be. A good way to put some life and performance back in a vintage rig.
W5LZ Rating: 2013-12-16
Very nice Time Owned: more than 12 months.
I've used Inrad filters for some time in several different radios. They do exactly what they claim to do, but do not 'do' miracles. I've found that they are certainly better than the typical manufacturer's filter.
Inrad used to also make a few 'doo-dads' for particular radios that would really slow the tuning dial's speed, they were very nice. (That should date me, it's been a while back.)I would recommend them for most radios.
- Paul
K4DXY Rating: 2013-12-16
Wonderful AM filter or Yaesu! Time Owned: 0 to 3 months.
There was NO way I was going to pay $140.00 + for a used Yaesu AM filter for my FT-840! A friend recommended that I look into the #1210 6000 Hz AM 8215 kHz 8-pole crystal filter from Inrad. Got it NEW for $136.95 shipped in about 3 days to my door! WOW - I can actually listen to Am now without pulling my hair out! Sounds like as million bucks now, as many people know - Yaesu made the FT-840 without any AM filter, the rig uses the stock 2.8 SSB filter for AM and of course sounds like Charlie Brown's teachers without the optional, rare, and expensive USED filter! At my request, Inrad even installed it on a plug-in board for me and was a perfect fit for the rig! I think the filter will work for several other radios, just email them and ask, great customer service, very happy, SWL is fun again!
WA1RKT Rating: 2013-06-26
Could use an installation warning Time Owned: 0 to 3 months.
Purchased a 1.8KHz 8.83 MHz filter for my Kenwood TS-950SDX. Seems to work OK but a couple of caveats about the installation that it would have been good if I could have been warned about ahead of time...

1. You have to cut two of the five pins off of one of the filter connectors on the TS-950SDX IF board, in order for the filter to fit. Those are ground pins that Inrad says are not needed or used, even for the Kenwood filters; still it would have been good to get a prior warning about this before purchase.

2. If you install the filter so that the writing on the label on top is the same direction as the Kenwood filters, it will interfere with the bottom shield of the TS-950SDX DSP unit and you will not be able to reinstall the radio's bottom cover. You have to install the filter "upside down" so that the label is upside down as compared with the labels on the Kenwood filters. The filters are bidirectional so it doesn't matter which way you install them, but a prior warning would have been nice so I didn't cut the pins off the wrong filter connector on the IF board (see (1) above).